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

Example Input: Problem: a fill pipe can fill 2 / 3 of cistern in 40 minutes in how many minutes , it can fill full of the cistern ? 
Options: a ) 60 min , b ) 36 min , c ) 25 min , d ) 30 min , e ) 50 min
Example Output: a

Example Input: Problem: a cube of side two meter length is cut into small cubes of side 10 cm each . how many such small cubes can be obtained ? 
Options: a ) 2878 , b ) 2778 , c ) 1000 , d ) 8000 , e ) 8900
Example Output: d

Example Input: Problem: a beaker contains 180 liters of alcohol . on 1 st day , 60 l of alcohol is taken out and replaced by water . 2 nd day , 60 l of mixture iss taken out and replaced by water and the process continues day after day . what will be the quantity of alcohol in beaker after 3 days 
Options: a ) 53.3 , b ) 53.8 , c ) 53.7 , d ) 53.5 , e ) 353.3
Example Output:
a