In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Example Input: Problem: what is the smallest no . which must be added to 532869 so as to obtain a sum which is divisible by 9 ? 
Options: a ) 9 , b ) 2 , c ) 1 , d ) 3 , e ) 6
Example Output: d

Example Input: Problem: on a race track a maximum of 5 horses can race together at a time . there are a total of 25 horses . there is no way of timing the races . what is the minimum number y of races we need to conduct to get the top 3 fastest horses ? 
Options: a ) 5 , b ) 7 , c ) 8 , d ) 10 , e ) 11
Example Output: b

Example Input: Problem: a and b are two partially filled buckets of water . if 5 liters are transferred from a to b , then a would contain one - third of the amount of water in b . alternatively , if 3 liters are transferred from b to a , b would contain one - half of the amount of water in a . bucket a contains how many liters of water ? 
Options: a ) 11 , b ) 13 , c ) 17 , d ) 49 / 5 , e ) 23
Example Output:
d