Final answer:
The triangles are congruent by HL when x = 5 and y = 4.
Step-by-step explanation:
In order for two triangles to be congruent using the HL (Hypotenuse-Leg) criterion, the hypotenuse and one of the legs of the triangles must be congruent.
In this case, x represents the adjacent side and y represents the opposite side of the triangles.
From the given answer choices, the only option where the triangles are congruent by HL is A. x = 5, y = 4. The hypotenuse for both triangles would be the same length (5) and one of the legs would be the same length (4).