Which mid-eighteenth century composer is credited with having the greatest impact on the significance of the string quartet?

a. Haydn

b. Mozart

c. Beethoven

d. Chopin

String quartet is a musical ensemble of four string players which includes two violin players, a cellist and a viola player. It is also referred to the piece written in order for the above-mentioned group to be played. Among the choices given, the correct answer is option A. The Austrian composer Joseph Haydn is credited with having the greatest impact on the significance of the string quartet.