question: Why did Buddy bark happily?
story: There once was a woman named Mary. Mary's best friend was a dog named Buddy. Mary and\newlineBuddy went everywhere together. They had a lot in common. They both liked to play games\newlinelike fetch and hide and seek. Neither of them liked to take a bath. Mary and Buddy enjoyed\newlinesmelling flowers and eating hamburgers. But they also were very different from one\newlineanother. For one thing, Buddy was a dog! Buddy liked talking to strangers and visiting new\newlineplaces. But Mary was shy. One day a man named John came by. Mary hid behind a tree when\newlineshe saw him. Buddy tried to tell her it was okay, but she was too scared to listen. So\newlineBuddy went out to say hello to John. John was very nice and he liked the same games as\newlineBuddy. Mary watched Buddy chase after a ball John threw. She could tell John was a nice\newlineman. She wanted to play too. Buddy saw her watching and led his new friend over to\newlineMary. John waved to Mary and brought her a flower. Mary smiled at him. She thought he was\newlinevery kind and she wasn't as nervous as before. Buddy barked happily. Yay for new friends!
answer_options.A: Because Mary was going to give him a bath.
answer_options.B: Because his new friend John became friends with Mary.
answer_options.C: Because John gave him a hamburger to eat.
answer_options.D: Because he found a beautiful flower to give to Mary.