Information:  - The phrase territorial police force varies in precise meaning according to the country to which it is related, generally distinguishing a force whose area of responsibility is defined by sub-national boundaries from others which deal with the entire country or a restricted range of crime.  - A molecule is an electrically neutral group of two or more atoms held together by chemical bonds. Molecules are distinguished from ions by their lack of electrical charge. However, in quantum physics, organic chemistry, and biochemistry, the term "molecule" is often used less strictly, also being applied to polyatomic ions.  - A police officer, also known as a policewoman, policeman, police agent is a warranted law employee of a police force. In the United States, "officer" usually is the formal name of the lowest police rank. In many other countries, "officer" is a generic term not specifying a particular rank, and the lowest rank is often "constable". In some nations the use of the rank "officer" is legally reserved for military personnel. Police officers are generally charged with the apprehension of criminals and the prevention and detection of crime, protection and assistance of the general public, and the maintenance of public order. Police officers may be sworn to an oath, and have the power to arrest people and detain them for a limited time, along with other duties and powers. Some police officers may also be trained in special duties, such as counter-terrorism, surveillance, child protection, VIP protection, civil law enforcement, and investigation techniques into major crime including fraud, rape, murder, and drug trafficking. Although many police officers wear a corresponding uniform, some police officers are plain-clothed in order to dissimulate as ordinary citizens.  - Deoxyribonucleic acid (DNA) is a molecule that carries the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and RNA are nucleic acids; alongside proteins, lipids and complex carbohydrates (polysaccharides), they are one of the four major types of macromolecules that are essential for all known forms of life. Most DNA molecules consist of two biopolymer strands coiled around each other to form a double helix.  - A virus is a small infectious agent that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea.  - Nucleic acids are biopolymers, or large biomolecules, essential to all known forms of life. They are composed of monomers, which are nucleotides made of three components: a 5-carbon sugar, a phosphate group, and a nitrogenous base. If the sugar is a simple ribose, the polymer is RNA (ribonucleic acid); if the sugar is derived from ribose as deoxyribose, the polymer is DNA (deoxyribonucleic acid).  - A macromolecule is a very large molecule, such as protein, commonly created by polymerization of smaller subunits (monomers). They are typically composed of thousands of atoms or more. The most common macromolecules in biochemistry are biopolymers (nucleic acids, proteins, carbohydrates and polyphenols) and large non-polymeric molecules (such as lipids and macrocycles). Synthetic macromolecules include common plastics and synthetic fibres as well as experimental materials such as carbon nanotubes.  - James Mackay QPM retired as Deputy Chief Constable of Tayside Police in 2001 . He has had considerable experience of criminal investigation and major inquiries . He is especially interested in forensic science and has served on national committees particularly in the field of DNA in police investigation .  - Tayside Police was a territorial police force covering the Scottish council areas of Angus, City of Dundee and Perth and Kinross (the former Tayside region) until 1 April 2013, at which point it was subsumed into Police Scotland. The total area covered by the force was with a population of 388,000. The force operated from 27 police stations and has an establishment of 1078 police officers, 151 special constables and 594 support staff, as of February 2008. Tayside Police was Scotland's fourth-largest police force.  - Life is a characteristic distinguishing physical entities having biological processes, such as signaling and self-sustaining processes, from those that do not, either because such functions have ceased, or because they never had such functions and are classified as inanimate. Various forms of life exist, such as plants, animals, fungi, protists, archaea, and bacteria. The criteria can at times be ambiguous and may or may not define viruses, viroids, or potential artificial life as "living". Biology is the primary science concerned with the study of life, although many other sciences are involved.  - Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation, and expression of genes. RNA and DNA are nucleic acids, and, along with proteins and carbohydrates, constitute the four major macromolecules essential for all known forms of life. Like DNA, RNA is assembled as a chain of nucleotides, but unlike DNA it is more often found in nature as a single-strand folded onto itself, rather than a paired double-strand. Cellular organisms use messenger RNA (mRNA) to convey genetic information (using the letters G, U, A, and C to denote the nitrogenous bases guanine, uracil, adenine, and cytosine) that directs synthesis of specific proteins. Many viruses encode their genetic information using an RNA genome.    After reading the paragraphs above, we are interested in knowing the entity with which 'james mackay ' exhibits the relationship of 'occupation'. Find the answer from the choices below.  Choices: - agent  - carbon  - major  - physics  - police  - police officer  - science
police officer