In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: two trains of equal length are running on parallel lines in the same directions at 46 km / hr . and 36 km / hr . the faster trains pass the slower train in 144 seconds . the length of each train is : 
Options: a ) 82 m , b ) 150 m , c ) 172 m , d ) 200 m , e ) none of these

Ex Output:
d


Ex Input:
Problem: the average of 6 quantities is 8 . the average of 4 of them is 5 . what is the avg . of the remaining 2 numbers ? 
Options: a ) 11 , b ) 12 , c ) 13 , d ) 14 , e ) 15

Ex Output:
d


Ex Input:
Problem: ( 0.0048 ) ( 3.5 ) / ( 0.05 ) ( 0.1 ) ( 0.004 ) = 
Options: a ) 8.4 , b ) 840 , c ) 84.0 , d ) 0.84 , e ) 0.084

Ex Output:

b