Answer:
Pair A:
The two triangles have two angles that are congruent, so by the Angle-Angle (AA) similarity theorem, they are similar.
Pair B:
The two triangles have two angles that are congruent, so by the Angle-Angle (AA) similarity theorem, they are similar.
Pair C:
The two triangles have two angles that are congruent, but they are not in the same order, so we cannot conclude that the triangles are similar.