In a mega-orchestra, the often provide the harmonies of the inner voices between high and low.
a. cellos
b. first violins
c. violas
d. second violins

In order to help the student expand his/her knowledge I will help answer the question. This in hope that the student will get a piece of knowledge that will help him/her through his/her homework or future tests.

The violas which are slightly lower in range than the violins often provide the harmonies of the inner voices between high and low. The correct choice is the letter

C. Violas

I hope it helps, Regards.      

Space and syfy is my opinion

Dynamic symmetry should be the answer