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: what is the measure of the angle e made by the diagonals of the any adjacent sides of a cube .
Options: ['a ) 30', 'b ) 45', 'c ) 60', 'd ) 75', 'e ) 90']

Ex Output:
c

Ex Input:
Problem: danny is sitting on a rectangular box . the area of the front face of the box is half the area of the top face , and the area of the top face is 1.5 times the area of the side face . if the volume of the box is 1536 , what is the area of the side face of the box ?
Options: a ) 34 , b ) 65 , c ) 88 , d ) 90 , e ) 128

Ex Output:
e

Ex Input:
Problem: the minimum number of tiles of size 16 by 24 required to form a square by placing them adjacent to one another is
Options: ['a ) 4 tiles', 'b ) 5 tiles', 'c ) 6 tiles', 'd ) 7 tiles', 'e ) 8 tiles']

Ex Output:
c