In a bilateral contract, have any parties acted yet?

In a bilateral contract, both parties have made promises to each other, but typically, neither party has yet fulfilled those promises at the time the contract is formed. A bilateral contract is characterized by an exchange of mutual promises, where one party agrees to perform a certain action in return for the other party's promise to perform a different action. Because the essence of the agreement lies in the promises exchanged, no actual performance has occurred at the initial point of the contract’s formation. This is why the correct answer states that no parties have acted yet, as they are both in the stage of promising rather than performing their obligations.

In contrast, the other options imply some level of action or performance, which is not inherent at the contractual formation phase of a bilateral contract. Thus, understanding the nature of bilateral contracts helps clarify why the correct choice emphasizes that the parties have not yet acted.