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

Example Input: Problem: a store has 10 bottles of juice , including 6 bottles of apple juice . in the evening , 6 bottles of juice are sold one by one . what is the probability of selling 2 bottles of apple juice among the 6 bottles ? assume that every bottle has an equal chance of being bought . 
Options: a ) 1 / 7 , b ) 1 / 12 , c ) 1 / 14 , d ) 1 / 18 , e ) 1 / 21
Example Output: c

Example Input: Problem: jane and thomas are among the 7 people from which a committee of 3 people is to be selected . how many different possible committees of 3 people can be selected from these 7 people if at least one of either jane or thomas is to be selected ? 
Options: a ) 20 , b ) 25 , c ) 30 , d ) 35 , e ) 40
Example Output: b

Example Input: Problem: a letter lock consists of 3 rings each marked with 6 different letters . the number of distinct unsuccessful attempts to open the lock is at the most - . 
Options: a ) 216 , b ) 243 , c ) 215 , d ) 729 , e ) 728
Example Output:
c