Information:  - The studio system (which was used during a period known as the Golden Age of Hollywood) is a method of film production and distribution dominated by a small number of "major" studios in Hollywood. Although the term is still used today as a reference to the systems and output of the major studios, historically the term refers to the practice of large motion picture studios between the 1920s and 1960s of (a) producing movies primarily on their own filmmaking lots with creative personnel under often long-term contract, and (b) dominating exhibition through vertical integration, i.e., the ownership or effective control of distributors and exhibition, guaranteeing additional sales of films through manipulative booking techniques such as block booking.  - An airline is a company that provides air transport services for traveling passengers and freight. Airlines utilize aircraft to supply these services and may form partnerships or alliances with other airlines for codeshare agreements. Generally, airline companies are recognized with an air operating certificate or license issued by a governmental aviation body.  - Silver Tree is a film producer, director and writer originally from Petaluma, California. She is most known for her independent film "The Aviary". She wrote the story and produced the movie with her husband Abe Levy, freely based upon her own life as a flight attendant. Silver Tree is the Directing Producer and Executive Producer of the US television series SUITS.  - Aircrew, also called flight crew, are personnel who operate an aircraft while in flight. The composition of a flight's crew depends on the type of aircraft, plus the duration and purpose of the flight.  - A feature film is a film (also called a movie, motion picture or just film) with a running time long enough to be considered the principal or sole film to fill a program. The notion of how long this should be has varied according to time and place. According to the Academy of Motion Picture Arts and Sciences, the American Film Institute, and the British Film Institute, a feature film runs for 40 minutes or longer, while the Screen Actors Guild states that it is 80 minutes or longer.  - An independent film or indie film is a feature film that is produced outside of the major film studio system, in addition to being produced and distributed by independent entertainment agencies.  - Flight attendants or cabin crew (also known as stewards/stewardesses, air hosts/hostesses, cabin attendants) are members of an aircrew employed by airlines primarily to ensure the safety and comfort of passengers aboard commercial flights, on select business jet aircraft, and on some military aircraft.  - Abe Levy is a writer/director originally from Tomales, California. His films include 'Max, 13', 'It's alright ma (I'm only trying)', 'The Aviary' and 'One of Our Own' as well as numerous short films and music videos. He often works with wife and writing/producing partner Silver Tree. He also works as a freelance editor and cameraman.  - The Aviary is a 2005 independent film about the ups and downs in the personal life of a flight attendant , coping with a transfer to a new city , finding a new love , and everything in between . It was written and produced by Abe Levy and Silver Tree , who was a flight attendant herself for many years .  - Tomales is a census-designated place (CDP) on State Route 1 in Marin County, California, United States. The population was 204 at the 2010 census. The largest employer in Tomales is Tomales High School, which has a student body of approximately 190.  - A major film studio is a production and film distributor that releases a substantial number of films annually and consistently commands a significant share of box office revenue in a given market. In the North American, Western, and global markets, the major film studios, often simply known as the majors, are commonly regarded as the six diversified media conglomerates whose various film production and distribution subsidiaries collectively command approximately 80 to 85 percent of U.S. and Canadian box office revenue. The term may also be applied more specifically to the primary motion picture business subsidiary of each respective conglomerate.  - Max, 13 is the 1999 debut feature film of director by Abe Levy, revolving around a 13-year-old boy coming of age in rural Northern California. This film featured Marshall resident, Max Hurwitz, who continues to reside in Marshall as well as Petaluma.    After reading the paragraphs above, we are interested in knowing the entity with which 'the aviary' exhibits the relationship of 'main subject'. Find the answer from the choices below.  Choices: - aviation  - city  - company  - film  - flight  - high school  - hollywood  - love  - music  - running  - television  - transport  - tree  - writer
A:
aviation