单项选择题

A、T0=(T11+T21+T31+T41+T51
B、T0=(T11+T21+T31+T41+T51)/5
C、T0=(T12~T11)+(T22~T21)+(T32~T31)+(T42~T42)+(T52~T51
D、T0=(T12~T11)+(T22~T21)+(T32~T31)+(T42~T41)+(T52~T51)/5