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 and b are two circles . the radius of a is four times as large as the diameter of b . what is the ratio between the areas of the circles ? 
Options: ['a ) 1 : 8 .', 'b ) 1 : 2 .', 'c ) 1 : 24 .', 'd ) 1 : 64 .', 'e ) 1 : 6 .']
Example Output: d

Example Input: Problem: the length of the diagonal of a square is 12 cm . find its area and perimeter . 
Options: ['a ) 31.84 cm', 'b ) 33.84 cm', 'c ) 35.84 cm', 'd ) 38.84 cm', 'e ) 38.92 cm']
Example Output: b

Example Input: Problem: the measure of the side of a square is multiplied by 7 . if x represents the perimeter of the original square , what is the value of the new perimeter ? 
Options: a ) 3 x , b ) 4 x , c ) 7 x , d ) 12 x , e ) 27 x
Example Output:
c