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 square with sides of length 12 centimeters is equal to the area of a rectangle with a width of 6 centimeters , what is the length of the rectangle , in centimeters ? 
Options: a ) 4 , b ) 8 , c ) 12 , d ) 24 , e ) 18
Example Output: d

Example Input: Problem: triangle atriangle b are similar triangles with areas 1792 units square and 2527 units square respectively . the ratio of there corresponding height would be 
Options: a ) 9 : 10 , b ) 17 : 19 , c ) 23 : 27 , d ) 16 : 19 , e ) 15 : 23
Example Output: d

Example Input: Problem: a ring x of diameter 16 inches is placed inside another ring y of diameter of 18 inches . how much fraction of the ring x surface is not covered by the ring y ? 
Options: ['a ) 13 / 15', 'b ) 12 / 4', 'c ) 16 / 17', 'd ) 22 / 16', 'e ) 17 / 81']
Example Output:
e