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: find the perimeter of a triangle with sides measuring 7 centimeters , 10 centimeters and 15 centimeters .
Options: ['a ) 10 cm', 'b ) 15 cm', 'c ) 32 cm', 'd ) 35 cm', 'e ) 20 cm']
Example Output: c

Example Input: Problem: the slant height of a cone is 13 cm and radius of the base is 9 cm , find the curved surface of the cone ?
Options: a ) 367 , b ) 378 , c ) 365 , d ) 26 , e ) 28
Example Output: a

Example Input: Problem: find the perimeter and area of a square of side 12 cm .
Options: a ) 144 , b ) 121 , c ) 169 , d ) 196 , e ) 100
Example Output:
a