The boys' motivation to take the football primarily stems from their desire to exhibit it to their friends. Option B.
How to explain
The boys took the football not to cause harm or get back at anyone but because they wanted to impress their friends. They thought borrowing it would make them look cool. They didn't think much about what might happen or that the football belonged to Mitsy.
They were so focused on trying to show off that they forgot to consider Mitsy's feelings or that it wasn't right to take something without asking. Their strong desire to be admired by their friends led them to take the football, showing how much they care about what others think of them.
The Complete Question
As the sun started going down, the boys hurried around the yard and noticed Mitsy's colorful football lying under her porch. They grinned mischievously and seemed very excited. Josh, who was the oldest, whispered, "Let's borrow it just for a while to show off to our friends. Mitsy never lets us play with it."
Everyone agreed with Josh's idea. Their plan was simple—they wanted to impress their friends by having the cool football. They didn't think much about whether it was okay or if Mitsy would mind. They felt a little bad about it but were so focused on wanting to look good in front of their friends that they took the ball without asking. They didn't realize there could be trouble because of what they did.