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: how many internal diagonals does a heptagon ( seven sided polygon ) have ?
Options: a ) 7 , b ) 9 , c ) 14 , d ) 20 , e ) 35
Example Output: c

Example Input: Problem: the area of a triangle will be when a = 2 m , b = 5 m , c = 7 m , a , b , c being lengths of respective sides ?
Options: a ) 2 , b ) 7 , c ) 5 , d ) 3 , e ) 4
Example Output: b

Example Input: Problem: if the area of a square with sides of length 6 centimeters is equal to the area of a rectangle with a width of 4 centimeters , what is the length of the rectangle , in centimeters ?
Options: a ) 4 , b ) 8 , c ) 12 , d ) 9 , e ) 18
Example Output:
d