Which of the following describes a unilateral contract?

A unilateral contract is characterized by an obligation on the part of only one party to perform certain actions under the terms of the agreement. In the context of insurance, this means that the insurer is the only party that has a legal obligation to fulfill the contract, such as paying claims when covered losses occur. The insured, in contrast, is not bound to perform any action beyond the payment of premiums.

This structure reflects the nature of many insurance policies, where the insurer assumes the risk and makes promises to provide coverage, while the insured is only required to pay premiums for that coverage. Because the insurer's promise constitutes the entire obligation of the contract, it is classified as unilateral.

In contrast, options that describe mutual obligations or require signatures from both parties do not accurately represent the essence of a unilateral contract as it exists in the realm of insurance contracts.