73.An company wants to determine the cost of equity to use in calculationg its weighted average cost of capital. The controller has gathered the following information:
rate of return on 3-month Treasury bills 3%
rate of return on 10-year Treasury bonds 3.5%
Market equity risk premium     6%
the comapny's estimated beta 1.6
the comapny's after-tax cost of debt 8%
risk premium of equity over debt 4%
corporate tax rate 35%

Using the capital asset pricing model(CAPM) approach, the cost of equity(%) for the company is closest to:

A. 7.5
B 12.6
C 13.1

我选的是B，因为我用rate of return on 3-month Treasury bills 做RFR，答案是C，用rate of return on 10-year Treasury bonds 做RFR。但是我看Notes上写大部分是用Treasury-bill做RFR，而教科书上说要看Project是长期还是短期的。不知道到底改用哪个做RFR？希望知道的同学解答。