Final answer:
A viola is included in a String Quartet, which is made up of two violins, one viola, and one cello, distinguishing it from brass, woodwind, and percussion ensembles.
Step-by-step explanation:
The type of ensemble that includes a viola is a String Quartet. A string quartet typically consists of two violins, one viola, and one cello. In contrast, a Brass Quintet comprises brass instruments such as the trumpet, trombone, and tuba; a Woodwind Quintet includes instruments like the flute, oboe, clarinet, bassoon, and horn; and a Percussion Ensemble would involve a variety of percussion instruments such as drums, xylophones, and cymbals. The viola, being a stringed instrument, belongs to the chordophones category in ethnomusicology classification.