Answer:
B. AAS
Explanation:
Let's see what we know:
We know that two angles are congruent, because OLM and ONM are given to be equal, and LMO and NMO are both 90 degrees.
That gives us AA.
Next, we can figure out that side LO = side ON, because of the Isosceles Triangle Theorem (if two angles of the big triangle LON are congruent, the two sides LO and ON are congruent).
Alternatively, we can figure out that side OM = OM, because of the reflexive theorem (it's the same side, so of course it's congruent to itself.) Thank you:)
Now we have AAS. Answer choice B is correct.