Which of Following Best Defines a Condition of a Contract

Which of following best defines a condition of a contract?

A) A term which expresses that no contract will come into being until one party has done a pre-agreed act
B) A term which is labelled as a condition by the parties to an agreement irrespective of the obligation it contains
C) A term of a contract that contains the parties fundamental obligations, which if breached would undermine the purpose of the entire agreement
D) A minor term which if broken gives the victim no potential to seek a remedy