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 lengths take 10 sec and 20 sec respectively to cross a telegraph post . if the length of each train be 120 m , in what time will they cross other travelling in opposite direction ? 
Options: a ) 16 sec , b ) 13 sec , c ) 17 sec , d ) 21 sec , e ) 23 sec

Ex Output:
b


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 20 seconds . find the length of the faster train ? 
Options: a ) 270 , b ) 277 , c ) 200 , d ) 257 , e ) 271

Ex Output:
c


Ex Input:
Problem: a person has to make 146 pieces of long bar . he take $ seconds to cut piece . what is total time taken by him to make 146 pieces ? 
Options: a ) 580 seconds , b ) 680 seconds , c ) 500 seconds , d ) 540 seconds , e ) 560 seconds

Ex Output:

a