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: the length of a rectangular garden is three times its width . if the area of the rectangular garden is 507 square meters , then what is the width of the rectangular garden ? 
Options: ['a ) 10', 'b ) 11', 'c ) 12', 'd ) 13', 'e ) 14']
Output:
d