Sam placed an announcement in the newspaper as follows: "$200 reward for the return of two lost Siamese kittens." Joe read the ad, found the kittens, and returned them. This is an example of which of the following? Select one: O a. Unilateral contract O b. Gratuitous promise O c. Offer O d. Bilateral contract e. Invitation to treat

Sam placed an announcement in the newspaper as follows: " $200 reward for the return of two lost Siamese kittens." Joe read the ad, found the kittens, and returned them. This is an example of which of the following? Select one: a. Unilateral contract b. Gratuitous promise c. Offer d. Bilateral contract e. Invitation to treat