After 15 Years of Contributions of $3,500 at the End

After 15 years of contributions of $3,500 at the end of every six months to a Retirement Savings Plan, the accumulated amount stood at $232,536. What semi-annually compounded nominal rate of return was earned by the funds in the RSP?

A) 2.5%
B) 5.0%
C) 7.5%
D) 10.0%
E) 12.5%