[求助]亲爱的们，帮忙看道数学题~~

If M and N are positive integers that
have remainders of 1 and 3, respectively,
when divided by 6, which of the
following could NOT be a possible
value of M+N?
(A) 86
(B) 52

(C) 34
(D) 28
(E) 10

请说明原因，谢谢~~

选A。

M=6X+1,N=6Y+3.M+N=6(X+Y)+4.

也就是说把每一个答案减掉四，如果不是六的倍数，就不可能是。