Fill in the given blanks with the correct option.

Her necklace was a perfect __________ to the gown, and she blushed when he gave her a sincere __________ on it.

The first blank requires a word meaning something that completes or makes perfect. Complement (with an 'e') fits this definition, as the necklace made the gown perfect.

The second blank requires a word meaning an expression of praise or admiration. Compliment (with an 'i') fits this definition, as he praised her necklace.

Complement (with an 'e') refers to something that completes or goes well with something else. Compliment (with an 'i') refers to an expression of praise.