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]: Erin asked Sarah for help with hanging the new bathroom mirror because _ is tall enough to reach. (A) Erin (B) Sarah
[EX A]: B

[EX Q]: Nick was given a dose of medication by Matthew because he had a fever. _ checked on him later. (A) Nick (B) Matthew
[EX A]: B

[EX Q]: The gemstone that he found on the mountain top was better than the stone because the _ was rare. (A) gemstone (B) stone
[EX A]:
A