Answer:
C. AC~= DF, FB~=CB
Explanation:
In order use HL theorem you have to have two right triangles, which it's marked that you do. HL stands for Hypotenuse-Leg. So in order to use Hypotenuse-Leg you have to know that the hypotenuses are congruent on the two triangles and also a leg is the same on the two triangles. AC and DF are the two hypotenuse. And FB and CB are legs. You need those two congruent segment pairs in order to use HL theorem.