You are given a sentence, a question and two answer options ('A' and 'B'). Your task is to find the correct answer (return the string of the correct option, not 'A' or 'B') for the given question.
--------
Question: Sentence: Janet is testing how much mass objects have. She is currently testing between a metal rod and a paper crane. She drops both from six feet in the air at the same time. Question: Which has stronger gravity? (A) metal rod (B) paper crane

Answer: metal rod


Question: Sentence: Danny is 5 years-old and Susan is 16. Their mom calls them inside for lunch. They both start running at the same time. Question: Who would get to lunch first? (A) Danny (B) Susan

Answer: Susan


Question: Sentence: One of Sarah's neighbors spilled dog food all over the stairs. The dog food pieces are on three stairways and all over the landings. Sarah gets mad and kicks a piece of dog food. The dog food flies across the wooden planks from one side of the staircase landing to the other. The dog food reaches the neighbor's door mat. It moves a few inches across the doormat. Question: Why didn't the dog food move further across the doormat? (A) The door mat is a spikier surface (B) the staircase landing is a spikier surface

Answer:
The door mat is a spikier surface