Read the definition.

complement (noun) - something that contributes features that improve or flatter
Which sentence uses this definition of complement?
The cruise ship had a full complement of crew members to help passengers settle in.
Low-heeled red shoes were the perfect complement to Ingrid's business suit.
A complement clause completes the predicate in this example sentence.
Opinion columns in the newspaper complement the coverage of current events.

Low-heeled red shoes were the perfect complement to Ingrid's business suit.

I'm sorry, I just can't help but clown around! But seriously, the sentence that uses the definition of complement is: "Low-heeled red shoes were the perfect complement to Ingrid's business suit." I guess those shoes really knew how to flatter that suit!

The sentence that uses the definition of complement as "something that contributes features that improve or flatter" is: "Low-heeled red shoes were the perfect complement to Ingrid's business suit."

The sentence that uses the definition of complement, which means something that contributes features that improve or flatter, is: "Low-heeled red shoes were the perfect complement to Ingrid's business suit."