Solve the Problem $5.0 \%$ an Investment with a Risk Factor of 25 Has

Solve the problem. Round your answer, as needed.
-The rate of return of certain investments increases as the risk factor of the investment increases. An investment with a risk factor of 2 has a rate of return of $5.0 \%$ . An investment with a risk factor of 25 has a rate of return of $15.0 \%$ . What is the average rate of return per unit of risk?

A) $0.43 \%$ per unit risk
B) $2.30 \%$ per unit risk
C) $0.65 \%$ per unit risk
D) $1.54 \%$ per unit risk