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: if the perimeter of a rectangular garden is 1800 m , its length when its breadth is 400 m is ?
Options: a ) 500 , b ) 600 , c ) 700 , d ) 800 , e ) 900
Example Output: a

Example Input: Problem: if 12 men and 16 boys can do a piece of work in 7 days and 13 men together will 24 boys can do it in 4 days . compare the daily work done by a man with that of a boy .
Options: a ) 1 : 4 , b ) 1 : 2 , c ) 1 : 3 , d ) 2 : 1 , e ) 4 : 1
Example Output: b

Example Input: Problem: two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively . if they cross each other in 22 seconds , what is the ratio of their speeds ?
Options: a ) 1 : 1 , b ) 3 : 1 , c ) 2 : 3 , d ) 3 : 2 , e ) 3 : 4
Example Output:
a