Synonyms are words which have the same or nearly the same meaning in the same language.
Antonyms are words which have opposite meaning in comparison to the other.
Option C)wise is correct as the word wise means having or showing experience, knowledge, and good judgementand the word dunce means a person who is slow at learning; a stupid person.
Both the words are opposite of each other.
The other options are not correct as they do not have the opposite meaning to the given word.