Given the task definition, example input & output, solve the new input case.
In this task, you need to provide the correct option for a given problem on probability from the provided options.
Example: Problem: in a throw of a coin find the probability of getting a tail ? 
Options: a ) 1 / 2 , b ) 1 / 3 , c ) 1 / 4 , d ) 2 / 5 , e ) 2 / 7
Output: a
"s = { h , t } e = { t } p ( e ) = 1 / 2 answer is a"

New input case for you: Problem: there are 8 pairs of socks and 2 socks are worn from that such that the pair of socks worn are not of the same pair . what is the number of pair that can be formed . 
Options: a ) 53 , b ) 54 , c ) 55 , d ) 56 , e ) 57
Output:
d