FanCo and FireCo form a contract that includes these terms:

• FanCo hereby promises and agrees that it will monitor the activities of FireCo's 400 franchisees throughout the United States, Europe, and Asia, and report its findings to FireCo once every three months in writing, according to details and specifications described in paragraphs 3 to 11 above, but FanCo will have no such obligation as to any nation if there should come to exist a state of war between it and any other nation anywhere.
• Every three months, FireCo will pay FanCo $4 million, representing $100,000 per franchise, except that it will make no payment as to any franchise for which during any three-month period FanCo fails to issue a report for any reason,.

If FireCo announces a waiver of the condition  beginning with the words "except that," and FanCo reasonably and foreseeably relies on the waiver to its detriment, will FireCo be empowered, thereafter, to retract its waiver?

A. No, because reasonable, foreseeable reliance always renders a waiver nonretractable

B. Yes, because as to this contract, FireCo's principal purpose is to receive FranCo's reports

C. Yes, because FanCo has the power to insist or not insist on a condition intended for its benefit

D. No, because such retraction would subject FanCo to an unfair surprise