Given the question: Information:  - The clavichord is a European stringed keyboard instrument known from the late Medieval, through the Renaissance, Baroque and Classical eras. Historically, it was mostly used as a practice instrument and as an aid to composition, not being loud enough for larger performances. The clavichord produces sound by striking brass or iron strings with small metal blades called tangents. Vibrations are transmitted through the bridge(s) to the soundboard.  - The Goldberg Variations, BWV 988, is a work written for harpsichord by Johann Sebastian Bach, consisting of an aria and a set of 30 variations. First published in 1741, the work is considered to be one of the most important examples of variation form. The "Variations" are named after Johann Gottlieb Goldberg, who may have been the first performer.  - Prelude in C Minor , BWV 999 ) , also termed The `` Little '' Prelude in C Minor , is a piece written by Johann Sebastian Bach sometime between 1717 and 1723 . Though originally composed for Lute - Harpsichord , it has since been adapted for various instruments , including lute , piano and guitar . It is a pedagogical work much in the spirit of The Well - Tempered Clavier , with which it shares musical characteristics . The piece 's true authorship fell into question for decades before being proven to be Bach 's by publication of Hans Neemann 's J. S. Bach Lautenkompositionen ( 1931 ) .  - A harpsichord is a musical instrument played by means of a keyboard. It produces sound by plucking a string when a key is pressed.  - A cantata (literally "sung", past participle feminine singular of the Italian verb "cantare", "to sing") is a vocal composition with an instrumental accompaniment, typically in several movements, often involving a choir.  - Johann Sebastian Bach (28 July 1750) was a German composer and musician of the Baroque period. He enriched established German styles through his skill in counterpoint, harmonic and motivic organisation, and the adaptation of rhythms, forms, and textures from abroad, particularly from Italy and France. Bach's compositions include the "Brandenburg Concertos", the "Goldberg Variations", the Mass in B minor, two Passions, and over three hundred cantatas of which around two hundred survive. His music is revered for its technical command, artistic beauty, and intellectual depth.  - A keyboard instrument is a musical instrument played using a keyboard. The most common of these are the piano, organ, and various electronic keyboards, including synthesizers and digital pianos. Other keyboard instruments include celestas, which are struck idiophones operated by a keyboard, and carillons, which are usually housed in bell towers or belfries of churches or municipal buildings.  - The Well-Tempered Clavier, BWV 846893, is a collection of two series of Preludes and Fugues in all 24 major and minor keys, composed for solo keyboard by Johann Sebastian Bach. In the German of Bach's time "Clavier" (keyboard) was a generic name indicating a variety of keyboard instruments, most typically a harpsichord or clavichord  but not excluding an organ either.    After reading the paragraphs above, choose the best answer for the entity that related to 'prelude in c minor' with the relationship of 'instrumentation'.  Choices: - choir  - harpsichord  - keyboard instrument  - organ
The answer is:
organ