Geometry

Answer: B

Explanation:

The original statement: If two angles are complementary, then their sum is 90 degrees. ✅ (True)
The converse: If the sum of two angles is 90 degrees, then they are complementary. ✅ (True)
Since both statements are true, they form a valid biconditional: "Two angles are complementary if and only if their sum is 90 degrees."

Analysis of Incorrect Options:

Option A: The original statement is true, but the converse "If a number is...