Builder Contracts to Construct Your House for $75,000

Multiple Choice

Builder contracts to construct your house for $75,000. Halfway through the project he stops and demands $10,000 extra. You agree because you won't have a place to live if you don't. You don't legally have to pay because there is

A) an existing obligation.
B) an impossible consideration.
C) equitable estoppel.
D) an unlawful consideration.
E) coercion.