While Mr P Was Walking Along a Busy Street, He Slumped

While Mr. P was walking along a busy street, he slumped and suffered from symptoms of a heart attack, and lost consciousness. Mr. D, a heart specialist saw what happened and through his expertise saved the life of Mr. P. If sued for Mr. D's services.

A) Mr. P must pay on the basis of an implied contractual relationship.
B) Mr. P must pay under a quasi-contract.
C) Mr. P has no obligation to pay because he did not ask for Mr. D's services.
D) Mr. P has no obligation to pay because the services of Mr. D can be construed as a voluntary act and hence, a donation.