(18) you are probably wondering how all of the rules and their exceptions will be remembered by you.
what is the best way to revise sentence (18)?
a) all of the rules and their exceptions need to be remembered by you.
b) you will probably need to remember all of the rules and their exceptions.
c) you are probably wondering how you will remember all of the rules and their exceptions.
d) how all of the rules and their exceptions will be remembered you are probably wondering.