Barbara, age 32, is thinking about investing for retirement. She plans to retire when she turns age 61. At that time, she will need $3.15 million in assets. She has calculated that inflation will average 2.90% over her lifetime. If she can earn an average annual 7.75% rate of return, what will be her real rate of return?

A. 4.85%.

B. 2.60%.

C. 4.71%.

D. 5.75%.