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

Example Input: Problem: a coin is tossed six times . what is the probability that there is at the least one tail ? 
Options: a ) 63 / 64 , b ) 31 / 37 , c ) 31 / 18 , d ) 31 / 10 , e ) 31 / 19
Example Output: a

Example Input: Problem: a coin is tossed 3 times . what is the probability of getting exactly 2 heads ? 
Options: a ) 1 / 2 , b ) 1 / 4 , c ) 3 / 8 , d ) 5 / 8 , e ) 3 / 16
Example Output: c

Example Input: Problem: in how many ways can 5 people be arranged in a circle ? 
Options: a ) 2 ! , b ) 5 ! , c ) 4 ! , d ) 3 ! , e ) 6 !
Example Output:
c

