Final answer:
The statement about three types of musical accompaniment is true, and a guitar is classified as a string instrument based on the sound produced by the vibration of its strings. The correct option is a.
Step-by-step explanation:
The statement 'The 3 types of accompaniment can be light guitar accompaniment, legato block chords, or broken chords arpeggios' is true. These are common ways to provide harmonic support to a melody in music. When studying music and musical instruments, a guitar would be classified based on the way sound is produced, which is primarily through the vibration of guitar strings that resonate through the body of the instrument and produce sound.
The body of the guitar acts as a resonating chamber for the sound, and while the air inside and surrounding the guitar does contribute to the sound production, it is not the primary factor. The ground beneath the musician has no significant role in the sound production of a guitar. Therefore, the guitar is classified as a string instrument because its sound is mainly due to the vibration of strings.
Hence, Option a is correct.