The correct answer is: C) about / to.
Complete Sentence:
People believe they will have no more worries about money if they win a huge sum to the lottery.
Explanation:
"Worries about money" is the natural phrasing, as we typically use "about" to specify the subject of concern or anxiety.
"Win a huge sum to the lottery" is a less common phrasing, but it's understood as the action of winning a prize related to the lottery.
If you find "to the lottery" a bit awkward, a more natural rewrite might be:
"...if they win a huge sum in the lottery."
Let me know if you’d like clarification!