How to do exact string match using another column as a reference?

I am currently trying to score a task where if a participant types a sentence, R will compare their response to a list of keyword. Each target keyword is given a column. My problem is I can't figure out how to look for exact matches only. For example, if the participant writes "cats" but the target keyword is "cat", it is scored as correct. I also don't think I can set boundaries, because the keywords change with each response. Attached is a screenshot of my current script . Thanks in advance!!

That is not a dataframe, that is a screenshot, can you turn this into a proper REPRoducible EXample (reprex) illustrating your issue?