题目内容：
What is the relationship between the severity of MS and level ofSlPR2?
A．A．The level of S 1 PR2 is higher, the MS is less severe． B．The level of S 1PR2 is higher, the MS is more severe．
C．The level of S 1 PR2 is lower, the MS is less severe．
D．The level of S 1 PR2 is lower, the MS is more severe．
参考答案：
答案解析：