The correct option is “Cassidy does not know which course she will register for.” This option avoids long grammar structures and makes it easier to read. The other two options are too wordy and use clauses that do not add meaning to the sentence. So the first option is better to avoid the overuse of formal language. Answer from: bryanmcmillianjr
Full Answer
the first one, - Cassidy does not know which course she will register for.
What is something that you were/are able to do during the pandemic that you would not have been able to do otherwise? Were/are there any good things t …