- paucity - scarcity
- propensity - tendency
- preponderance - the quality or fact of being greater in number, quantity, or importance.
- accuracy - correctness
- plaintiff means a person who brings a case against another in a court of law.
"_________ of evidence was on the side of the plaintiff since all but one witness testified that his story was correct."
So, here it means that the "plaintiff" brought a case to the court and all but one witness supported him and so he has "plenty of evidence" in support.
Correct option: C