题目内容 (请给出正确答案)
提问人:网友d*******1 发布时间:2023年8月5日 09:36
[单项选择题]

月经的发生是由于血中()。

A.雌激素急剧减少

B.孕激素急剧减少

C.雌激素和孕激素急剧减少

D.前列腺素减少

E.雄激素减少

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