Why Is the Fundamental Breach Rule Defunct? Please Select All

Why is the fundamental breach rule defunct? Please select all that apply.

A) Major difficulties were faced in attempts to describe a 'fundamental' term.
B) The very nature of the doctrine of fundamental breach made it impossible to construct a rational theory, which undermined legal certainty.
C) It contradicts a basic principle of contract law; that it is for the parties, and not the court, to make the bargain.
D) It could be excluded where the contract is affirmed after a fundamental breach has been committed.