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 men a and b start from place x walking at 4 ½ kmph and 5 ¾ kmph respectively . how many km apart they are at the end of 4 ½ hours if they are walking in the same direction ? 
Options: a ) 7 km , b ) 6 km , c ) 5 5 / 8 km , d ) 9 km , e ) 5 km

Ex Output:
c


Ex Input:
Problem: two trains are moving in opposite directions at 60 km / hr and 90 km / hr . their lengths are 2.9 km and 1.6 km respectively . the time taken by the slower train to cross the faster train in seconds is ? 
Options: a ) 99 , b ) 277 , c ) 48 , d ) 96 , e ) 108

Ex Output:
e


Ex Input:
Problem: p and q can complete a work in 15 days and 10 days respectively . they started the work together and then q left after 2 days . p alone completed the remaining work . the work was finished in - - - days . 
Options: a ) 12 , b ) 16 , c ) 20 , d ) 24 , e ) 28

Ex Output:

a