Answer:
C: exceptional, common
Explanation:
The word pair that has opposit denotations is exceptional, common. Denotation is the main meaning of a word, without the feelings or ideas connected to things that people may have.
Exceptional: unusual; not like others of the same type. much greater than usual, specially in skill, intelligence, quality, etc. A garden of exceptional beauty.
Common: the same in a lot of places or for a lot of people. In the same way as someone or something. "Smith" is a very common name in Britain.
