Don promised to buy his girlfriend, Sophie, a new car so Sophie sold her old car. Don now refuses to buy Sophie the car. Sophie has a job that...

Don promised to buy his girlfriend, Sophie, a new car so Sophie sold her old car. Don now refuses to buy Sophie the car. Sophie has a job that requires her to have a car to get to work. If Sophie sues Don to enforce the promise, the likely result is that the promise will:

A. Be enforced under promissory estoppel because Sophie reasonably relied on Don's promise, to her detriment.

B. Not be enforced as Sophie was not unjustly enriched simply because she did not receive the car.

C. Be enforced because the car is a necessity for Sophie and all contracts for necessities are binding and enforceable for all parties even if contract formation is flawed.

D. Not be enforced as Don’s promise was a gift to Sophie; Sophie gave consideration, but Don did not.

Is the correct answer A or D? Please explain.