Which of the following best describes a breach of contract?

A breach of contract is best described as a failure to fulfill contractual obligations. This means that one party has not performed their duties as outlined in the agreement, whether that be by not delivering goods, failing to pay, or not completing services as promised. Such a failure can lead to legal consequences and can give the other party the right to seek remedies, which might include damages or specific performance.

While negotiating terms after signing the contract and modifying contract terms without consent relate to contract management, they do not necessarily indicate a breach unless the negotiation or modification is not permissible under the existing contract's terms. Verbal disagreements between parties might arise but do not inherently constitute a breach either. In essence, a breach is directly tied to the non-performance of the specific duties established in the contract, which makes the definition of a breach as a failure to fulfill those obligations both precise and fundamental to contract law.