Which pair illustrates a complementarity relationship between words?

• A. Employer and employee
• B. Bread and water
• C. Moon and sun
• D. Teacher and student

Answer: (A)

Complementarity in word pairs means two terms that complete a single system by representing two essential, interdependent roles. In employment, the two sides clearly define the whole relationship: the employer creates the job, resources, and supervision, while the employee provides labor and skills. Each term depends on the other to constitute the full concept of employment; neither alone describes the relationship completely.

Bread and water are both basic necessities but don’t form a single, interdependent system that defines a role or function. Moon and sun are natural counterparts, but they’re more about dual presence than a mutually dependent role within one system. Teacher and student reflect a learning dynamic and are also complementary, but the employer–employee pairing most cleanly illustrates two terms that complete a single social relationship by mutual reliance.