问题详情

What does Dr. Luiders study tell us about the pregnancy zone protein？

A．It never increases before the appearance of Alzheimer"s symptoms.

B．Levels of it remain stable for men"s lifetime.

C．Women developing Alzheimer"s usually have lower levels of it.

D．The brain plaques connected with Alzheimer"s produce it.

请帮忙给出正确答案和分析，谢谢！