In this task, you need to answer the given multiple-choice question on geometry. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: 6 points lie on the circumference of a ellipse . what is the positive difference between the number of triangles and the number of quadrilaterals that can be created by connecting these points ? 
Options: a ) 4 , b ) 6 , c ) 5 , d ) 15 , e ) 20

Ex Output:
c


Ex Input:
Problem: tough and tricky questions : number properties . what is the smallest positive integer x such that 1512 x is the cube of a positive integer ? 
Options: a ) 7 , b ) 14 , c ) 28 , d ) 35 , e ) 49

Ex Output:
e


Ex Input:
Problem: the surface area of a sphere is 4 π r 2 , where r is the radius of the sphere . if the area of the base of a hemisphere is 3 , what is the surface area q of that hemisphere ? 
Options: a ) 6 / π , b ) 9 / π , c ) 6 , d ) 9 , e ) 12

Ex Output:

d


