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: in the rectangular coordinate system , points ( 4 , 0 ) and ( – 4 , 0 ) both lie on circle c . what is the maximum possible value of the radius of c 
Options: a ) 2 , b ) 4 , c ) 8 , d ) 16 , e ) none of the above
Example Output: b

Example Input: Problem: find the surface area of a 8 cm x 4 cm x 2 cm brick . 
Options: a ) 136 cu cm , b ) 112 cu cm , c ) 164 cu cm , d ) 180 cu cm , e ) none
Example Output: b

Example Input: Problem: a rectangular tank needs to be coated with insulation . the tank has dimensions of 3 feet , 6 feet , and 2 feet . each square foot of insulation costs $ 20 . how much will it cost to cover the surface of the tank with insulation ? 
Options: ['a ) $ 980', 'b ) $ 1060', 'c ) $ 1220', 'd ) $ 1440', 'e ) $ 1650']
Example Output:
d