Roddy Richards invested​ $12014.88 in Wolverine Meat Distributors​ (W.M.D.) five years ago. The investment had yearly arithmetic returns of minus−​9.7%, minus−​8.1%, ​15%, 7.2%, and​ 15.4%. What is the arithmetic average return of Roddy​ Richard's investment?
A. ​4.63%
B. ​8.78%
C. ​6.96%
D. ​3.38%