What are considered to be the most important terms within a contract compared to some others? Which of the following is correct?

Some terms in a contract are so fundamental to the contract that non compliance essentially means the contract has not been carried out in any meaningful way, thus allowing the party suffering the breach to rescind

The most important terms in a contract are the warranties, these are terms whereby the parties 'warrant' that these terms must be complied with, or the contract comes to an end

The most important terms in a contract are innominate terms, these are nominated as the essential terms of the contract and must be complied with or the contract is nullified by statutory provisions

All terms within a contract have equal importance; any breach of any term will terminate a contract