The best answer that describes a difference between the two stories is:
B: In “Lost and Found,” the narrator and her sister find a kitten on their front porch. In “My New Friend Sammy,” the narrator gets a pet snake from the pet shop.
This response accurately highlights the distinct circumstances under which the pets are acquired in each story. In "Lost and Found," the kitten is found, while in "My New Friend Sammy," the snake is bought from a pet shop.