The following table shows the average beta for corporate bonds with different levels of credit ratings.

Avg. Beta

By Rating A and above - <0.05

BBB - 0.1

BB - 0.17

B - 0.26

CCC - 0.31

a) According to this table, on average, which type of securities have a higher cost of capital: corporate bonds or stocks? You only need to write down either corporate bonds or stocks.

b) What is the fundamental economic reason that explains your answer in part a.? Please limit your answer to 2 sentences. (Hint: the correct answer is beyond CAPM)