In the past few decades, the influence of political parties has

In the past few decades, the influence of political parties has been declining ______.
A、so the political parties are no longer important
B、so an independent presidential candidate can win a national election
C、but without the backing of a political party, a presidential candidate still cannot win
D、so the presidential election has become more unpredictable
【正确答案】：C
【题目解析】：根据课本P245可知，在过去的几十年里，政党的影响力一直在下降，但是没有政党的支持，总统候选人仍然无法获胜。