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

Input: Consider Input: Problem: what is the probability of getting exactly 2 heads in a single throw of four fair coins ? 
Options: a ) 1 / 2 , b ) 3 / 4 , c ) 3 / 8 , d ) 3 / 16 , e ) 5 / 16

Output: c


Input: Consider Input: Problem: a bag contains 3 red , 5 yellow and 4 green balls . 3 balls are drawn randomly . what is the probability that balls drawn contain exactly two green balls ? 
Options: a ) 9 / 16 , b ) 7 / 18 , c ) 12 / 55 , d ) 14 / 67 , e ) 19 / 87

Output: c


Input: Consider Input: Problem: there are 20 balls in a jar . you take out 2 blue balls without putting them back inside , and now the probability of pulling out a blue ball is 1 / 5 . how many blue balls were there in the beginning ? 
Options: a ) 12 . , b ) 9 . , c ) 8 . , d ) 7 . , e ) 6 .


Output: a