Which Statement Is NOT an Explanation for Why Germany and Japan

Which statement is NOT an explanation for why Germany and Japan both grew faster than the United States following World War II?

A) Both countries had very little capital stock remaining after the war.
B) Both countries had a high marginal product of capital after the war.
C) Both countries had strong incentive to put new capital stock into place.
D) Both countries were experiencing cutting-edge growth at the time.