Trace an Array from an element

I’m making a test. There are multiple questions on the screen at once. What I’m going to do is have each answer choice for a question in an array for each question and each answer choice will have a mouse click event listener. That listener will call a function that will highlight the selected option.
Here’s where my problem comes up. I don’t want them to be able to select multiple choices, so when they select a different answer choice, within the same problem, the highlight needs to move from their previous choice to the new choice. How do I best do this? I was wondering if there was a way to find out what array a selected element belongs to.