Take another look at the item:

While Professor Koopman explained the consequences of the French Revolution, (A) Tiffany and Faith sniffled uncomfortably in their seats, (B) suffocated by the cheap shaving lotion (C) that Henry always wore.

You wanted to do this:

While Professor Koopman explained the consequences of the French Revolution, Tiffany and Faith sniffled uncomfortably in their seats, suffocated by the cheap shaving lotion, that Henry always wore.

A comma after lotion is incorrect. That Henry always wore is a subordinate clause. Generally, when you connect a clause of this type to the end of a sentence, you need no punctuation.

You might want to review the rules.

Go back to the sentence to try again.

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