In this task, you are given a question containing a blank (_) and two options. You should pick the best option to answer the question. Please answer with "A" or "B".

[EX Q]: Aaron went to pick up Michael, who needed a ride to the airport, and _ was very grateful. (A) Aaron (B) Michael
[EX A]: B

[EX Q]: The teacher of Nick was a lot smarter than Robert's teacher, because _ teacher has several degrees. (A) Nick (B) Robert
[EX A]: A

[EX Q]: The little boy picked the ball from the mud, rubbed it over his cloth and got the _ dirty. (A) ball (B) cloth
[EX A]:
B