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.

Sentence: Bob took his toy car outside to play with it. He rolled it on the street and then he rolled it in the grass. He noted that the toy car rolled much faster in the street. Question: Which surface caused more friction? (A) The street (B) The grass
The grass

Sentence: Dom and Brian race their fast cars down a quarter mile stretch of road. Dom's car is faster than Brian's. Question: Who wins the race? (A) Brian (B) Dom
Dom

Sentence: Two chimps in a zoo always like to throw apples into the neighboring zebra enclosure. Zippy always seems to throw the apples further than Toby. Question: Which chimp is weaker? (A) Zippy (B) Toby
Toby