Question: Bob likes to skip rocks across the lake. He skipped rocks on a calm day when the lake was smooth and on a windy day when the lake was choppy. He noticed that the rock encountered less friction on the smooth lake than the choppy lake. Which lake would the rock skip farther on? (A) The smooth lake (B) The choppy lake  Do not use A and B to answer the question but instead, choose between "smooth lake" and  "choppy lake".
A:
smooth lake