Answer:
McDonald's will prevail.
Step-by-step explanation:
First of all, in a franchise agreement, the the franchisee is economically dependent on the franchisor's business system. Their relationship is defined by the contract. C.B.'s failure to make timely payments did constitute a breach of the franchise contract. So McDonald's had the right to terminate the agreement, since the payments were more than 30 days late.
The contract didn't provide that the acceptance of a late payment waived McDonald's right to terminate for late payments. And the implied covenant of good faith and fair dealing requires that both parties act reasonably. McDonald's previous acceptance of late payments didn't affect their contract rights.