The mean return of a portfolio is 20% and its standard deviation is 4%. The returns are normally distributed. Which of the following statements about this distribution are least accurate The probability of receiving a return:（）

A. of less than 12% is 0.025.

B. between 12% and 28% is 0.95.

C. in excess of 16% is 0.16.

依据《煤矿安全监察条例》的规定，煤矿安全监察机构发现煤矿矿井使用的设备、器材、仪器、仪表、防护用品不符合国家安全标准或者行业安全标准的，应当( )。

A．责令立即停止作业
B．责令立即关闭矿井
C．责令限期改正
D．责令立即停止使用