单项选择题

A.体重(kg)=出生体重(kg)+月龄×0.7(kg)
B.体重(kg)=6(kg)+月龄×0.25(kg)
C.体重(kg)=年龄×2+7(kg)
D.体重(kg)=年龄×2+8(kg)
E.体重(kg)=年龄×7+77(kg)