Answer:
Option C
The ability to have an effect on the behavior, character, or actions of someone else
Explanation:
The word influence has quite a number of meanings which may vary based on the context which it is used.
We can analyse the situation presented in the problem statement "Dara could influence my decision to vote for Joy in the student body election " to find the meaning based on this context.
We understand that the influence used here most likely means that Dara can affect the choice I make for a candidate during the election. If this happens it means that Dara can affect my behaviour, character or action, as regards to taking a decision during the election.
This makes option C the most appropriate answer