Answer:C. EVENTUALLY
Explanation: An Adverb is a word used to describe,modify or qualify a verb, adjective,clause etc. It helps to give a better and clearer meaning to a verb,an adjective,clause etc.
With an adverb attached to any of the parts of speech it make it easier to understand and comprehend.
EVENTUALLY in this situation is an adverb as it helps to qualify the word SENT. Other examples of adverb includes CAREFULLY,AFTER, ACTUALLY, EXTREMELY, ABRUPTLY etc.