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: a train running at a speed of 60 kmph crosses a pole in 18 seconds . what is the length of the train ? 
Options: a ) 120 m , b ) 300 m , c ) 190 m , d ) 150 m , e ) 160 m

Ex Output:
b


Ex Input:
Problem: circular gears p and q start rotating at the same time at constant speeds . gear p makes 10 revolutions per minute and gear q makes 40 revolutions per minute . how many seconds after the gears start rotating will gear q have made exactly 5 more revolutions than gear p ? 
Options: a ) 6 , b ) 8 , c ) 10 , d ) 12 , e ) 15

Ex Output:
c


Ex Input:
Problem: the current of a stream runs at the rate of 4 kmph . a boat goes 10 km and back to the starting point in 2 hours , then find the speed of the boat in still water ? 
Options: a ) a ) 7 , b ) b ) 2 , c ) c ) 8.9 , d ) d ) 11.4 , e ) e ) 3

Ex Output:

d