Please answer and explain:

QUESTION 16 All of the following are true about the marginal tax rate for the firm except for O The marginal tax rate in the U.S. is usually about 40%. O The effective tax rate is usually less than the marginal tax rate Once tax credits have been used and the ability to further defer taxes exhausted, the effective rate can exceed the marginal rate at some point in the future It is critical to use the effective tax rate in calculating after-tax operating income in perpetuity. O It is critical to use the marginal rate in calculating after-tax operating income in perpetuity