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: the ratio of the radius of two circles is 1 : 3 , and then the ratio of their areas is ? 
Options: a ) 1 : 5 , b ) 1 : 6 , c ) 1 : 9 , d ) 1 : 3 , e ) 1 : 2
Example Output: c

Example Input: Problem: a certain cube floating in a bucket of water has between 75 and 85 percent of its volume below the surface of the water . if between 9 and 16 cubic centimeters of the cube ' s volume is above the surface of the water , then the length of a side of the cube is approximately 
Options: ['a ) 4', 'b ) 5', 'c ) 7', 'd ) 8', 'e ) 9']
Example Output: a

Example Input: Problem: if the perimeter and diagonal of a rectangle are 14 and 5 cms respectively , find its area . 
Options: ['a ) 12 cm 2', 'b ) 16 cm 2', 'c ) 20 cm 2', 'd ) 24 cm', 'e ) none of these']
Example Output:
a