Set - 4

The guiro, a musical instrument traditionally made from a dried and hollowed gourd, is thought to have originated with the Taino people of Puerto Rico. Players use a wooden stick to scrape along ridges cut into the side of the gourd, creating sounds that are highly _________: the sounds produced by guiros can differ based on the distance between the ridges, the types of strokes the player uses, and the thickness of the gourd.

Which choice completes the text with the most logical and precise word or phrase?