Which is an example of sarcasm?

a."john has strong organizational skills," his teacher exclaimed. "his notebook is as organized as a library."

b. bobby showed up for his date with jennifer with a bouquet of flowers in his hand. jennifer exclaimed, "why, you're a regular romeo! "

c. tammy is like a walking dictionary — she can spell any word at any time!

d. my little brother was flying his kite in the front yard when a neighbor came out and asked, "are you flying a kite? " my brother answered, "nope, just fishing for birds."