Which of the following is an example of a bilateral contract?

A bilateral contract is an agreement in which both parties exchange mutual promises to perform certain actions. In this case, the second party's obligation to make a payment corresponds directly with the first party's obligation to sell the item. Each party has made a commitment that is contingent on the other party's performance, creating a binding contract.

When one party promises to sell something in exchange for payment, it indicates a mutual exchange: the seller agrees to provide goods or services, and the buyer agrees to compensate the seller. This mutuality is essential for a contract to be classified as bilateral.

In contrast, a promise to give a ride or to paint a fence does not necessarily involve a return promise or expectation of performance, which does not satisfy the criteria for a bilateral contract. Additionally, a promise to donate to charity may not involve any reciprocal obligations, further highlighting that it does not fit the definition of a bilateral contract.