请教一个倍数问题 (OG72 and xdf补充80)

我想请问"increase by four times" or "increase by more than four times" 这种用法对不对？有没有重复的嫌疑？先请看下面一题：
OG72题
The number of undergraduate degrees in engineering awarded by colleges and universities in the United States increased by more than twice from 1978 to 1985.
(A) increased by more than twice
(B) incrased more than two times
(C) more than doubled
(D) was more than doubled
(E)had more than doubled
答案是C。它对A的解释是“A is faulty because an adverb such as twice cannot function as an object of preposition by." 那么如果这里是4倍，比如说"increased by more than 4 times", 这种用法对吗？
再看这题，新东方补充语法的80题：
SInce 1970 the number of Blacks elected to state and federal officers in the United States has multiplied nearly four times
(A) has multiplied nearly four times.
(B) has almost quadrupled
(C) has almost multipled by four
(D) is almost four times as great
(E) is nearly fourfold what it was
答案是B。请问A改成has multiplied by nearly four times,C改成has almost multiplied by four times才对？还是说multiply这里用法不对？如果再多一个选择“has increased by nearly four times”，这个选择对吗？
谢谢！