单选题 The U.S. achieved its predominance after World War Ⅱ because ______.

A、 it had made painstaking efforts towards this goal
B、 its domestic market was eight times larger than before
C、 the war had destroyed the economies of most potential competitors
D、 the unparalleled size of its workforce had given an impetus to its economy

【正确答案】 C

【答案解析】第一段的末尾“America and Americans were prosperous beyond the dreams of the Europeans and Asians whose economies the war had destroyed”可以得出[C]是美国在战后达到繁荣的原因。