单选题 According to Leszezynski, how does mobile phone affect one's health?

A、 Mobile phone radiation can increase protein activities and such activities can make the protective shield more permeable.
B、 Mobile phone radiation can shrink the blood vessels and prevent blood from flowing smoothly.
C、 Mobile phone radiation will bring stress to people exposed to it.
D、 Mobile phone radiation kills blood cells at a rapid speed.

【正确答案】 A

【答案解析】文章论述的是手机导致人体细胞变化，所以从“The study found that a protein called hsp27 linked to the functioning of the blood-brain barrier showed increased activity due to irradiation and pointed to a possibility that such activity could make the shield more permeable(能透过的)．”可以判断答案是A。