Logic design k-map question
The point of minimizing a boolean function is that you want to output the same 0s and 1s with the smallest number of terms. A don't care can be either a 0 or a 1 - whichever makes the function simpler.

In your case, there's no reason to treat the entire CD' block of don't cares as 1s: if it doesn't make your SOP function simpler, don't add it.

I think the simplest SOP expression is AC' + A'C. Here's a picture of those two terms.