Answer: The answer is (A) complementary angles.
Step-by-step explanation: We are given a figure involving angles 1 and 2 and we are to select the correct relation between these two angles.
We have

We know that, if the sum of two angles is 90°, then they are said to be complementary angles.
Thus, ∠1 and ∠2 are complementary angles.
Thus., (A) is the correct option.