The answer is a triad (C). A triad is a type of chord that consists of three pitches on consecutive lines or spaces. Hope this helps!
An orchestra is defined as a large instrumental ensemble typical of classical music. An orchestra features bass, brass, strings, woodwinds, and percussions. In the list given above, the section that is not one of the four groups in the orchestral palette is the voices. The answer would be "voices".
