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 field is to be fenced on three sides leaving a side of 20 feet uncovered . if the area of the field is 440 sq . feet , how many feet of fencing will be required ? 
Options: a ) 34 , b ) 40 , c ) 64 , d ) 88 , e ) 92
Example Output: c

Example Input: Problem: the diameter of a circle is 4 / π . find the circumference of the circle . 
Options: ['a ) 8', 'b ) 4 π', 'c ) 4', 'd ) 6', 'e ) 5']
Example Output: a

Example Input: Problem: the surface area of a sphere is same as the curved surface area of a right circular cylinder whose height and diameter are 10 cm each . the radius of the sphere is 
Options: a ) 3 cm , b ) 5 cm , c ) 6 cm , d ) 8 cm , e ) none
Example Output:
b