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'.

Ex Input:
Problem: two trains of equal length , running with the speeds of 60 and 40 kmph , take 36 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 sec , b ) 16 sec , c ) 19 sec , d ) 7.2 sec , e ) 13 sec

Ex Output:
d

Ex Input:
Problem: convert 0.34 in to a vulgar fraction ?
Options: a ) 18 / 50 , b ) 16 / 50 , c ) 17 / 50 , d ) 19 / 50 , e ) none

Ex Output:
c

Ex Input:
Problem: the l . c . m of two numbers is 2310 and their h . c . f is 30 . if one number is 210 the other is
Options: a ) 330 , b ) 300 , c ) 270 , d ) 250 , e ) 350

Ex Output:
a