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 3 bottles of apple juice among the 6 bottles ? assume that every bottle has an equal chance of being bought . 
Options: a ) 2 / 11 , b ) 4 / 15 , c ) 6 / 17 , d ) 8 / 21 , e ) 10 / 25
Example Output: d

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

Example Input: Problem: there are 22 students in a class . in how many different ways can a committee of 3 students be formed ? 
Options: a ) 1180 , b ) 1320 , c ) 1540 , d ) 1760 , e ) 1920
Example Output:
c

