Find the complementary angle of 30 degrees.

To find the complementary angle of a given angle, you subtract that angle from 90 degrees. The definition of complementary angles states that two angles are complementary if their sum is equal to 90 degrees.

In this case, you have an angle of 30 degrees. To calculate its complementary angle, you perform the following calculation:

90 degrees - 30 degrees = 60 degrees.

This means that the angle that, when added to 30 degrees, equals 90 degrees is 60 degrees. Therefore, the complementary angle of 30 degrees is indeed 60 degrees.

This method confirms that option B is the correct answer, as it satisfies the requirement of being complementary to the original angle. Other choices do not fulfill the definition of complementary angles in relation to 30 degrees.