26. What effect does this quoted language have on enforceability of the promise?

A promise is supported by consideration if two things are true: (i) the promisee is giving up something of value or circumscribes his liberty in some way to suffer a legal detriment; and (ii) the promisor makes his promise as part of a bargained-for exchange for the promisee's legal detriment.

Under the pre-existing duty rule, if a party does or promises to do what he is already legally obligated to do, or if he forebears or promises to forebear from doing something which he is not legally entitled to do, he has not incurred the kind of legal detriment necessary to constitute consideration.

An illusory promise is a statement that appears to be promising something but does not actually commit the promisor to anything at all. One kind of illusory promise is when a promisor reserves the right to change his mind, which does not bind him to anything. Such an illusory promise is not supported by consideration. For example, a promise is illusory if, by its terms, the promisor unconditionally reserves the right of alternative performances (e.g., «I'll buy it if I feel like it.»). The modern approach, however, is that whenever possible, courts should construe a promise so as not to be illusory. Thus, if the promisor's right to change his mind is limited by some objective standard, consideration is likely to be found and the contract upheld. A promise that reserves several alternative performances may be supported consideration if each of the alternative performances would have been sufficient consideration if it had been bargained for alone.

A promise that would otherwise be illusory may be supported by consideration if, for example, the court reads into the promise an obligation to exercise discretion in good faith. So long as the promisor has limited his freedom of action in some way, the court will find consideration sufficient to enforce the return promise.

A voidable promise or contract exists when a party to the contract has the power to disaffirm the agreement for some specific legal reason, such as the existence of fraud, duress, or infancy.

D is correct. In applying the modern approach of construing a promise to be non-illusory whenever possible, the woman's promise to pay $100 «as soon as I am able» effectively limited her freedom of action because, if it can be demonstrated that she becomes able to pay, she will become obligated to do so.

A is incorrect. This language does not cause the promise to be voidable, as it does not justify any specific legal reason to void the contract, such as duress, fraud, or infancy.

B is incorrect. It is incorrect that this language renders the promise illusory; a court will construe the quoted language to limit the woman's freedom of action in some way, as stated above.

C is incorrect. This answer choice invokes a doctrine under the UCC that does not apply to this question. The seller (and not the woman) will bear the burden of demonstrating that the condition has been satisfied.