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: if the area of a circle decreases by 30 % , then the radius of a circle decreases by
Options: a ) 20 % , b ) 16 % , c ) 36 % , d ) 64 % , e ) none of these
Example Output: b

Example Input: Problem: the diameter of a cylindrical tin is 14 cm and height is 2 cm . find the volume of the cylinder ?
Options: a ) 33 , b ) 45 , c ) 66 , d ) 77 , e ) 98
Example Output: e

Example Input: Problem: the length of a rectangle is three times of its width . if the length of the diagonal is 8 10 then find the perimeter of the rectangle .
Options: ['a ) 77 cm', 'b ) 88 cm', 'c ) 64 cm', 'd ) 11 cm', 'e ) 18 cm']
Example Output:
c