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: the ratio of efficiency of a is to c is 5 : 3 . the ratio of no . of days taken by b is to c is 2 : 3 . a takes 6 days less than c , when a and c completes the work individually . b and c left the work after 2 days . the no of days taken by a to finish the remaining work ?
Options: a ) 4.5 , b ) 5 , c ) 6 , d ) 7 , e ) 8
Example Output: c

Example Input: Problem: some persons can do a piece of work in 12 days . two times the number of these people will do half of that work in ?
Options: a ) 3 , b ) 4 , c ) 5 , d ) 6 , e ) 8
Example Output: a

Example Input: Problem: two trains of equal length , running with the speeds of 60 and 100 kmph , take 50 seconds to cross each other while they are running in the same direction . what time will they take to cross each other if they are running in opposite directions ?
Options: a ) 10 , b ) 6.25 , c ) 7.35 , d ) 2.62 , e ) 2.28
Example Output:
b