A and B Agree in Writing That a Will Renovate

A and B agree in writing that A will renovate B's house for $20 000.00.A renovates the house and B pays the money.In this situation

A) the contract has been discharged by performance.
B) the parties are free to go on to do whatever they like.
C) all the obligations under the contract have been met by A and B.
D) the contract is at an end.
E) all of the above