Given the task definition and input, reply with output. 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: A knob rolled across a wooden table travels at a lower rate of speed then one rolled across a metal table. Question: Which surface provides more friction to the knob? (A) wooden table (B) metal table

B