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: in what time will a railway train 110 m long moving at the rate of 36 kmph pass a telegraph post on its way ? 
Options: a ) 6 sec , b ) 7 sec , c ) 8 sec , d ) 11 sec , e ) 2 sec

Ex Output:
d


Ex Input:
Problem: in what time will a train 100 metres long cross an electric pole , if its speed be 144 km / hr ? 
Options: a ) 2.5 sec , b ) 4.25 sec , c ) 5 sec , d ) 12.5 sec , e ) none

Ex Output:
a


Ex Input:
Problem: two trains are moving in the same direction at 72 kmph and 36 kmph . the faster train crosses a man in the slower train in 25 seconds . find the length of the faster train ? 
Options: a ) 270 , b ) 250 , c ) 187 , d ) 257 , e ) 271

Ex Output:

b