Step-by-step explanation:
The player can recover the $5,000 because the preexisting duty rule does not apply where the duty is owed to a third person.
The player can recover because, under the prevailing modern rule, the preexisting duty rule does not apply if the duty is owed to a third person. Generally, contracts must be supported by consideration. A promise to perform is valid consideration, but if a person already owes a duty to perform, traditionally that performance cannot be used as consideration for another promise. Thus, under the traditional rule, the player could not enforce the father's promise to pay the player $5,000 if he hit a home run because the player gave no valid consideration in exchange for the father's promise, since the player owed a preexisting duty to his ball club to exert his best efforts to hit home runs. However, under the modern view as formulated in Restatement (Second) of Contracts, section 73, and followed by a majority of courts, a duty is a preexisting duty only if it is owed to the promisee. Thus, a promise to perform a duty is valid consideration as long as the duty of performance is not already owed to the promisee. In other words, if the duty is owed to a third party, a promise to perform given to another is valid consideration as long as it was bargained for. (B) is incorrect because there is no exception to the preexisting duty rule—modern or otherwise—that allows the promisor to recover merely because his performance benefited a third party. The player can recover under the modern approach because his promise to the father was bargained for. Conversely, the player does not have to prove that the value of his home run to the boy was at least $5,000, because courts generally will not inquire into the adequacy of consideration. (C) would be correct under the traditional rule, but, under the modern trend, the promise here is valid consideration because the duty to hit home runs was owed to a third party (the ball club) rather than to the promisee (the father). (D) is incorrect because while it is true that moral consideration is not good consideration, the father did not rely on moral consideration, but rather exchanged a promise to pay $5,000 for the player's performance.