Answer:
c = -d/a + b
Explanation:
I'm honestly not sure why it doesn't give you that answer choice but all I did was simplify and isolate c. So first divide both sides of the equation by a and then subtract b which would leave you with -c = d/a - b. However, c cannot be negative so you have to multiply both sides of the equation by -1 to cancel out the negative. You would be left with c = -d/a + b.