Answer:
A
Explanation:
First, the list of congruence theorems are:
SSS
SAS
ASA
AAS
HL
SSA is not on the list, so we can cross that out
Next, ASA implies that two angles are congruent, but we only know that one pair of angles (the right angles) are congruent, so we can cross that out
After that, the angle is not connecting the congruent sides, so D is not an option
Finally, we know that the longest sides (AD / AC) are congruent to each other, one other pair of legs/sides are congruent, and the triangles are both right triangles. Therefore, we can apply HL here