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 man and a boy complete a work together in 24 days . if for the last 6 days man alone does the work then it is completed in 26 days . how long the boy will take to complete the work alone ? 
Options: a ) 72 days , b ) 20 days , c ) 24 days , d ) 36 days , e ) 34 days
Example Output: a

Example Input: Problem: two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 21 seconds . the ratio of their speeds is ? 
Options: a ) 3 / 6 , b ) 3 / 2 , c ) 2 / 3 , d ) 3 / 5 , e ) 5 / 2
Example Output: c

Example Input: Problem: a boy wants to make cuboids of dimension 5 m , 6 m and 7 m from small cubes of . 03 m 3 . later he realized he can make same cuboids by making it hollow . then it takes some cubes less . what is the number of the cubes to be removed ? 
Options: ['a ) 1000', 'b ) 2000', 'c ) 3000', 'd ) 4000', 'e ) 5000']
Example Output:
e