Geometry

Question Analysis:
The question tests whether you recognize the correct conditions for HL congruence.

Key Concept Explanation:
HL applies only to right triangles where one leg and the hypotenuse are congruent.

Step-by-Step Solution:
Option A: 🚫 Just a pair of legs is not enough.
Option B: 🚫 HL only applies to right triangles, not isosceles triangles.
Option C: ✅ Correct conditions for HL.
Option D: 🚫 Equilateral triangles use SSS, not HL.