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'.

Input: Consider 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

Output: a


Input: Consider Input: Problem: two passenger trains start at the same hour in the day from two different stations and move towards each other at the rate of 12 kmph and 21 kmph respectively . when they meet , it is found that one train has traveled 60 km more than the other one . the distance between the two stations is ? 
Options: a ) 477 , b ) 396 , c ) 279 , d ) 276 , e ) 291

Output: b


Input: Consider Input: Problem: in what time will a railway train 56 m long moving at the rate of 39 kmph pass a telegraph post on its way ? 
Options: a ) 3 sec , b ) 4 sec , c ) 5 sec , d ) 6 sec , e ) 7 sec


Output: c