Instructions: In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
Input: Problem: a man walked diagonally across a square lot . approximately , what was the percent saved by not walking along the edges ?
Options: ['a ) 20 %', 'b ) 30 %', 'c ) 40 %', 'd ) 50 %', 'e ) 55 %']
Output:
b