You will be given a definition of a task first, then some input of the task.
You are given a sentence, a question and two answer options. Your task is to write down the index ('A' or 'B') of the **incorrect** option for the given question.

Sentence: Toby went ice skating during the winter and noticed that he hardly had to put any effort into moving forward when he switched from the sidewalk to the ice on the pond. Question: Which surface was smoother? (A) Sidewalk (B) Ice pond
Output:
A