In a unilateral contract, what is true about the obligations of the parties?

In a unilateral contract, only one party has made a promise to perform a certain action, while the other party's obligation is conditional upon the performance of that action. This means that Party A is the one who has committed to fulfill a promise, such as providing a reward for a specific action taken by another party, which would be Party B.

The nature of unilateral contracts is that there is an offer that creates an obligation for one party only – the promisor – while the other party, the promisee, is not obligated to act but may choose to do so in order to receive the benefit of the promise. For example, if someone offers a reward for a lost pet, they are the only party bound by the promise of the reward, and the person finding the pet has the option to act but is not required to do so.

This understanding of unilateral contracts clarifies that only one party has the binding promise, which is what makes the answer correct.