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: approximately how many cubic feet of water are needed to fill a circular swimming pool that is 100 feet across and 4 feet deep ? 
Options: a ) 15000 , b ) 30000 , c ) 50000 , d ) 70000 , e ) 90000
Example Output: b

Example Input: Problem: the slant height of a cone is 22 cm and radius of the base is 7 cm , find the curved surface of the cone ? 
Options: a ) 426 , b ) 284 , c ) 483 , d ) 256 , e ) 428
Example Output: c

Example Input: Problem: the radius of a cylindrical vessel is 8 cm and height is 3 cm . find the whole surface of the cylinder ? 
Options: a ) 308 sq cm , b ) 220 sq cm , c ) 440 sq cm , d ) 553.1 sq cm , e ) 138 sq cm
Example Output:
d