求助一道prep 关于while 和at the same time

luciole

Q40.    p2-sc     45.    (26816-!-item-!-188;#058&003335)

A recent poll indicates that many people in the United States hold a combination of conservative and liberal political views; i.e., they denounce big government, saying government is doing too much and has become too powerful, while at the same time supporting many specific government programs for health care, education, and the environment.

(A) they denounce big government, saying government is doing too much and has become too powerful, while at the same time supporting
(B) they denounce big government--they say that government is doing too much and has become too powerful--but supporting at the same time
(C) they denounce big government, they say that government is doing too much and it has become too powerful, while they support at the same time
(D) while they denounce big government, saying that government is doing too much and has become too powerful, at the same time supporting
(E) while they are denouncing big government--they say that government is doing too much and it has become too powerful-- supporting at the same time
答案是A
不过我就想知道while 和 at the same time如果都是指同时可以一起使用吗？应该不行吧，当然这里我觉得答案里面while是作为转折和对比的意思，不存在重复，但是如果有那种情况存在，应该是不能放在一起吧？
还有一个疑问，这里while是连词，但是并未连接句子，而是连接两个伴随状语，这样子语法上面没问题吗？

luciole

继续求解答~~~欢迎讨论啊！

luciole

晕，原来我忘记加下划线，怪不得没人来看这道题，实在不好意思！！

luciole

.....没人理我提的问题是太简单了么。。。

luciole

顶一下，期待nn解答，大家一起讨论啊~