Answer: The correct answer is "b.relieves Nero of liability on the check.".
Explanation: If on the back of a check payable to Nero, Nero writes "Pay to Odell, without recourse" and signs it. This relieves Nero of liability on the check.
Nero writing "pay Odell, without recourse" on the back of the check, transmits the rights of the title, but adding the clause "without recourse" that frees Nero from the responsibility for the payment of the check, that is, in In case of non-payment, Odell can not take action against Nero, but against the drawer of the check or other obligors that respond jointly and severally.