In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: a rectangular courtyard 3.78 meters long 5.25 meters wide is to be paved exactly with square tiles , all of the same size . what is the largest size of the tile which could be used for the purpose ? 
Options: ['a ) 14 cms', 'b ) 21 cms', 'c ) 42 cms', 'd ) none of these', 'e ) 56 cms']

Ex Output:
b


Ex Input:
Problem: what is the area of a square field whose sides have a length of 13 meters ? 
Options: a ) 225 sq m , b ) 169 sq m , c ) 128 sq m , d ) 267 sq m , e ) 231 sq m

Ex Output:
b


Ex Input:
Problem: the area of a circle of radius 5 is numerically what percent of its circumference ? 
Options: ['a ) 200', 'b ) 225', 'c ) 240', 'd ) 250', 'e ) none']

Ex Output:

d