Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Compared to the efficient frontier of risky assets, the dominant capital allocation line has higher rates of return for levels of risk greater than the optimal risky portfolio because of the investor’s ability to:
Option A:lend at the risk-free rate.
Option B:borrow at the risk-free rate.
Option C:purchase the risk-free asset.

Answer: B