单项选择题

用程序计算一个整数的各位数字之和,在下划线处应填写的语句是( )。
SET TALK OFF
INPUT "X=" TO X
S=0
DO WHILE X!=0
S=S+MOD(X,10)
______
ENDDO
S
SET TALK ON

A.X=int(X/10)
B.X=int(X%10)
C.X=X-int(X/10)
D.X=X-int(X%10)