Answer:
B) No contract was formed because Fine received Moss' acceptance after April 4.
Explanation:
The mailbox rule established that an acceptance is effective if it has been sent by a means authorized by the offeror, or by the same means used to sent the offer.
Fine Corp. didn't state by what means it would accept an offer, but if Moss would have faxed his acceptance at 23:59 April 4th, the acceptance would have been valid. But since Moss used an overnight mail service, his acceptance was not received on time and therefore is not effective.