Sports Bar and Tasty Tacos are adjacent businesses with adjoining parking lots. Sports Bar offers Tasty a discount on purchases if the restaurant will not tow the cars of Sports Bar$$s patrons who park in the restaurant$$s lot. The discount is legally sufficient consideration

a$.$ because the offeror considers it to be adequate.

b$.$ because it is a promise of something of value.

c$.$ under no circumstances.

d$.$ because on acceptance, it will become a preexisting duty.