Which describes the correct instrumentation for a string quartet?

The answer is Two violins, one viola, one cello. 

Beethoven was a deaf man and couldnt hear. he became famous for his classical pieces. and there ye go.vivaldi was a true one hit wonder classical artist. hes known for his classical piece the four seasons. he was although wasn't as great as beethoven and yea 'ere ye a go.

This is called adduction