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

Ex Input:
Problem: the contents of two vessels containing copper and tin in the ratio 1 : 2 and 2 : 5 are mixed in the ratio 1 : 4 . the resulting mixture will have copper and tin in the ratio ? 
Options: a ) 15 : 32 , b ) 21 : 28 , c ) 31 : 74 , d ) 33 : 37 , e ) 41 : 92

Ex Output:
c


Ex Input:
Problem: if two dice are thrown together , the probability of getting prime number on both dice is 
Options: a ) 5 / 9 , b ) 1 / 9 , c ) 2 / 9 , d ) 4 / 9 , e ) 7 / 9

Ex Output:
c


Ex Input:
Problem: 20 balls are numbered 1 to 20 . a ball is drawn and then another ball is drawn without replacement . what is the probability that both balls have even numbers ? 
Options: a ) 7 / 30 , b ) 3 / 14 , c ) 9 / 38 , d ) 4 / 21 , e ) 5 / 26

Ex Output:

c