Is It Correct to Put Plurals in Parentheses in a Listening Answer?

Jessica and Aubrey answer a question about spelling in listening. If we are not sure about whether the answer is car or cars, is it correct to write the plural in the brackets like car and then in parentheses and ask? I love this question on so many levels. It's fantastic. It's wrong. You can't do this guys. Like the grammar matters on the listening exam. Whether there's an S or not affects the grammar,.Whether it's a plural or subject verb agreement. All of these things have to be correct for you to get the answer right.