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: the least perfect square , which is divisible by each of 21 , 36 and 66 is 
Options: a ) 213414 , b ) 213424 , c ) 213434 , d ) 213444 , e ) none of these

Ex Output:
d


Ex Input:
Problem: in the xy - plane , a triangle has vertices ( 0,0 ) , ( 4,0 ) and ( 4,8 ) . if a point ( a , b ) is selected at random from the triangular region , what is the probability that a - b > 0 ? 
Options: a ) 1 / 5 , b ) 1 / 3 , c ) 1 / 2 , d ) 2 / 3 , e ) 4 / 5

Ex Output:
c


Ex Input:
Problem: find the area of a parallelogram with base 26 cm and height 14 cm ? 
Options: a ) 287 cm 2 , b ) 887 cm 2 , c ) 364 cm 2 , d ) 368 cm 2 , e ) 668 cm 2

Ex Output:

c