I did this question by plugging numbers
We know that W = 4 + M and W + M = 10
Out of these choices, only D satisfies above two conditions
If W = 7 then M = 3
There are 4 more women than men on Centerville’s board of education. If there are 10 members on the board, how many are women?
Given: M=W-4 so, W+(W-4)=10 --> W=7.