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 volume of a rectangular swimming pool is 840 cubic meters and water is flowing into the swimming pool . if the surface level of the water is rising at the rate of 0.5 meters per minute , what is the rate r , in cubic meters per minutes , at which the water is flowing into the swimming pool ? 
Options: a ) 0.125 , b ) 0.25 , c ) 0.5 , d ) 0.75 , e ) not enough information to determine the rate
Example Output: e

Example Input: Problem: sides of a triangle are 13 cm . 14 cm . and 15 cm . respectively . calculate the area of triangle . 
Options: ['a ) 80', 'b ) 82', 'c ) 84', 'd ) 86', 'e ) 88']
Example Output: c

Example Input: Problem: a semicircle has a radius of 12 . what is the approximate perimeter of the semicircle ? 
Options: a ) 58 , b ) 62 , c ) 66 , d ) 70 , e ) 74
Example Output:
b