Where One Party Refuses to Perform His Contractual Obligations, What

Where one party refuses to perform his contractual obligations, what is the risk that the second party runs if he continues to press the first party to perform?

A) The first party may continue to refuse to perform, and there is nothing the second party can do about that.
B) The contract may be discharged by frustration.
C) The first party might expressly repudiate the contract and therefore not be liable for breach.
D) The first party might breach a condition subsequent.
E) The second party might receive more damages for which he can't recover compensation.