题目：给一个不多于5位的正整数，要求：一、求它是几位数，二、逆序打印出各位数字。x = int(input("input a number:"))a = x // 10000________________c = x % 1000 // 100d = x % 100 // 10e = x % 10if a != 0:print ("there are 5 ",e,d,c,b,a)elif b != 0:print ("there are 4 ",d,c,b,a)elif c != 0:print ("there are 3 ",e,d,c)elif d != 0:print ("there are 2 ",e,d)else:print ("there are 1",e)

A. b = x // 10000 // 1000
B. b = x % 10000 // 1000
C. b = x // 10000 % 1000
D. b = x % 10000 % 1000