In this task, you need to provide the correct option for a given problem from the provided options.

Ex Input:
Problem: the ratio between the sale price and the cost price of an article is 6 : 5 . what is the ratio between the profit and the cost price of that article ? 
Options: a ) 2 : 9 , b ) 1 : 5 , c ) 3 : 6 , d ) 2 : 0 , e ) 2 : 1

Ex Output:
b


Ex Input:
Problem: evaluate 50 ! / 47 ! 
Options: a ) 102500 , b ) 112584 , c ) 117600 , d ) 118450 , e ) 128450

Ex Output:
c


Ex Input:
Problem: a bag contains 8 red , 6 blue and 4 green balls . if 2 ballsare picked at random , what is the probability that both are red ? 
Options: a ) 1 / 13 , b ) 2 / 23 , c ) 5 / 26 , d ) 7 / 30 , e ) 3 / 23

Ex Output:

d