Correct option is B
The correct option to fill in the blank is (b) compliment; complements.
Explanation:
Compliment: A polite expression of praise. (प्रशंसा)
Complement: Something that enhances or goes well with something. (पूरक)
Example:
Thank you for your compliment on my dress. It really complements my style.
Meanings of other options and why they are incorrect:
Complaints: Expressions of dissatisfaction (शिकायतें)
Compliments: Right word but second blank needs complements
Complement; complements: First blank needs an expression of praise, not "complement"