Answer:
The pair of words that is made up of synonyms is C. assent/consent.
Step-by-step explanation:
A synonym is a word or phrase that means exactly, or at least nearly the same as another in the same language in some or many senses. Within these options, the pair that is made up of synonyms is C because to assent means to approve of something or to agree, and to consent means to give approval or assent, so they share the same meaning in that sense.