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

Example Input: Problem: in a throw of a coin find the probability of getting a head ? 
Options: a ) 1 / 2 , b ) 1 / 3 , c ) 1 / 4 , d ) 2 / 3 , e ) 2 / 5
Example Output: a

Example Input: Problem: if a coin is flipped , the probability that the coin will land tails is 1 / 2 . if the coin is flipped 4 times , what is the probability that it will land tails up on the first 2 flips and not on the last 2 flips ? 
Options: a ) 1 / 4 , b ) 1 / 8 , c ) 1 / 2 , d ) 1 / 16 , e ) 1 / 32
Example Output: d

Example Input: Problem: when 3 fair coins are tossed together , what is the probability of getting 2 tails ? 
Options: a ) 1 / 2 , b ) 1 / 3 , c ) 1 / 4 , d ) 3 / 4 , e ) 2 / 3
Example Output:
a