This is a hard one and I can see why you decided to post it here. B is most definitely wrong but the other three are all neck and neck. There are both even pros and cons of A and C but I think it would be more reasonable to adopt a general routine. So I think the answer would be C.
For ye shall hear, how our heavenly king
Calleth Everyman to a (general reckoning).
If the letter you are referring to is the one you get when you have your credit card account or bill delivered to your home, then the best answer would be most likely the second one. The letter provides the recipient information about the condition of his own bank account.
Trevor is Neville Longbottom’s toad and he is found by Hagrid, the groundskeeper, as he was checking the boats