Which of the Following Is True with Regard to Ending

Which of the following is true with regard to ending a contract by performance, agreement, or breach?

A) A contract can be ended by breach if there was a either a breach of condition or a breach of warranty.
B) A person has legally tendered performance if he pays a $500 debt in 25-cent coins.
C) If a person properly tenders performance of a service that is rejected by the other party, he is required to try again and again.
D) A contract ends by agreement when the parties include in the contract a "condition subsequent," i.e., a clause that says the contract will end upon the happening of a specified future event that then takes place.
E) If one party to the contract has paid for a service, but now the other doesn't want to perform, the contract is ended by agreement as long as they both agree to call it off.