The koto is: _____________
a. a Japanese board zither, without movable bridges, similar to the Chinese qin (guqin)
b. an instrument that is used in some gagaku music, as a solo instrument, and in small ensembles
c. a Japanese chordophone that looks very much like a banjo
d. a board zither chordophone that was first brought to China from Japan during the Meiji Restoration period
