Harry owns a racehorse named "Thunder." It's a "mudder," meaning that it runs best on a wet, muddy track. Harry plans to enter Thunder in the upcoming National Horse Race. Jackson is a jockey, famous for his ability to ride mudders and famous, too, for his unwillingness to ride a mudder on a dry track. Harry and Jackson agree that if, on the day of the race, the track is muddy, Harry will ride Thunder. If it's dry, he won't. In exchange, Harry promises to pay Jackson $5,000, unconditionally, when the race is over. That means he promises to pay Jackson even if the track is dry, meaning that Jackson does not ride in the race. He agrees to pay Jackson even if, as things turn out, Jackson does nothing. On the day of the race the track is dry. Another jockey rides Thunder. Jackson does nothing. Because the track is dry, Thunder finishes in last place. When the race is over, Jackson demands that Harry pay him $5,000. Is Harry obliged to pay Jackson the $5,000 he demands?
A.Yes, because Jackson's promise constituted consideration to Harry
B.Yes, because Thunder did run the race
C.No, because Jackson made only an aleatory promise and Harry made an unconditional one
D.No, because as matters turned out, Harry derived no benefit from Jackson's promise.