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

Example Input: Problem: a rectangular rug with side lengths of 2 feet and 7 feet is placed on a square floor that has an area of 64 square feet . if the surface of the rug does not extend beyond the area of the floor , what fraction of the area of the floor is not covered by the rug ? 
Options: ['a ) a . 3 / 16', 'b ) 1 / 4', 'c ) c . 1 / 2', 'd ) 25 / 32', 'e ) 7 / 8']
Example Output: d

Example Input: Problem: the perimeter of a triangle is 36 cm and the inradius of the triangle is 2.5 cm . what is the area of the triangle 
Options: a ) a ) 72 , b ) b ) 45 , c ) c ) 729 , d ) d ) 34 , e ) e ) 35
Example Output: b

Example Input: Problem: the diameters of two spheres are in the ratio 1 : 2 what is the ratio of their volumes ? 
Options: a ) 1 : 9 , b ) 1 : 2 , c ) 1 : 8 , d ) 1 : 1 , e ) 1 : 6
Example Output:
c