Choose those statements that are correct:

a. Modigliani and Miller argued that with perfect capital markets, the total value of a firm should not depend on its capital structure.

b. Leverage increases the risk of equity even when there is no risk that the firm will default.

c. Modigliani and Miller's conclusion states that even with perfect capital markets without any frictions, leverage would affect a firm's value.

d. Investors in levered equity require a higher expected return to compensate for its increased risk