[Logic question] sum of products for that using k-map

Question

Hi,

I have a logic question:

If I have: f(A,B,C,D) = M(4,7,8,11).D(1,2,13,14)

what would be the sum of products for that using k-map (please note that this is big-m and you have to find the answer in the sum of products)

I drew the k-map, the problem is, I can't find a way to cover the zeros without having to state 4 terms each with 4 boolean terms (A,B,C,and D) without using the D terms, is that right?

Note: this is a homework question, i don't want the answer as much as i want to be able to solve this myself.

   +---+---+---+---+
00 | 1 | 0 | 1 | 0 |
   +---+---+---+---+
01 | x | 1 | x | 1 |
   +---+---+---+---+
11 | 1 | 0 | 1 | 0 |
   +---+---+---+---+
10 | x | 1 | x | 1 |
   +---+---+---+---+
     00  01  11  10

I edited the map because it was made for little m and this is big m