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

Example Input: Problem: what is the probability of getting a sum of 8 or 14 when rolling 3 dice simultaneously ? 
Options: a ) 1 / 6 , b ) 1 / 4 , c ) 1 / 2 , d ) 21 / 216 , e ) 32 / 216
Example Output: a

Example Input: Problem: the chance of rain on any given day in tel - aviv is 50 % . what is the probability a that it rained in tel - aviv on exactly 4 out of 6 randomly chosen days ? 
Options: a ) 15 / 64 , b ) 30 / 64 , c ) 1 / 2 , d ) 1 / 4 , e ) 52 / 64
Example Output: a

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