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

Ex Input:
Problem: a meeting has to be conducted with 3 managers . find the number of ways in which the managers be selected from among 6 managers , if 2 managers will not attend the meeting together ? 
Options: a ) 18 , b ) 20 , c ) 16 , d ) 22 , e ) 24

Ex Output:
c


Ex Input:
Problem: from a pack of 52 cards , 1 card is drawn at random . what is the probability that a red card is drawn ? 
Options: a ) 1 / 2 , b ) 1 / 4 , c ) 1 / 26 , d ) 1 / 13 , e ) 5 / 13

Ex Output:
a


Ex Input:
Problem: if a certain coin is flipped , the probability that the coin will land heads is 1 / 2 . if the coin is flipped 6 times , what is the probability that it will land heads up on the first 4 flips but not on the last 2 flips ? 
Options: a ) 1 / 8 , b ) 1 / 16 , c ) 1 / 32 , d ) 1 / 64 , e ) 1 / 128

Ex Output:

d