a reflection is a rigid transformation, meaning that the size and shape of the figure does not change. therefore, the length of C'D' will be the same as the length of CD.
When you plug in the numbers for the integers, you get 8.2-2(-3.7) If you multiply -2 and -3.7, you get 7.4 because the negatives cancel each other out. If you then add 8.2, you get 15.6. So the answer is D. Hope it Helps! :)
