Final answer:
A 'small 45' is a miniature vinyl disc known as a 45 RPM record, typically measuring 7 inches in diameter and used for single hits of music, making option A) A miniature vinyl disc the correct answer.
Step-by-step explanation:
The "small 45" referred to in the question is most likely a miniature vinyl disc, known as a 45 RPM record. These vinyl records typically measure 7 inches in diameter and are intended to be played at a speed of 45 revolutions per minute. They gained popularity due to their portable size and ability to be played on smaller, more convenient record players. 45s were widely used for single hits and are an important part of music history, as they were used to distribute rock, pop, and other genres of music during the mid-20th century.
These vinyl records differ significantly from compact cassettes, which are magnetic tape sound recording formats, or musical playlists which are modern digital compilations of songs. Additionally, a "small 45" is not related to a documentary film.
In summary, a small 45 or 45 RPM record is the correct answer, which is option A) A miniature vinyl disc.