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 water level in a rectangular swimming pool measuring 50 feet by 25 feet is to be lowered by 6 inches . how many gallons of water must be removed ? ( 1 cu ft = 7.5 gallons ) 
Options: a ) 100 , b ) 250 , c ) 750 , d ) 1200 , e ) 4687.5
Example Output: e

Example Input: Problem: if the radius of a circle is increased by 40 % then the area is increased by : 
Options: a ) 44 % , b ) 120 % , c ) 96 % , d ) 40 % , e ) none of the above
Example Output: c

Example Input: Problem: the parameter of a square is equal to the perimeter of a rectangle of length 18 cm and breadth 10 cm . find the circumference of a semicircle whose diameter is equal to the side of the square . 
Options: a ) 44.0 , b ) 23.59 , c ) 23.55 , d ) 23.53 , e ) 23.57
Example Output:
a