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: if the perimeter of a rectangular garden is 1800 m , its length when its breadth is 400 m is ? 
Options: a ) 500 , b ) 600 , c ) 700 , d ) 800 , e ) 900

Ex Output:
a


Ex Input:
Problem: the ratio of efficiency of a is to c is 5 : 3 . the ratio of no . of days taken by b is to c is 2 : 3 . a takes 6 days less than c , when a and c completes the work individually . b and c left the work after 2 days . the no of days taken by a to finish the remaining work ? 
Options: a ) 4.5 , b ) 5 , c ) 6 , d ) 7 , e ) 8

Ex Output:
c


Ex Input:
Problem: natasha climbs up a hill , and descends along the same way she went up . it takes her 4 hours to reach the top and 2 hours to come back down . if her average speed along the whole journey is 4 kilometers per hour , what was her average speed ( in kilometers per hour ) while climbing to the top ? 
Options: a ) 2 , b ) 2.5 , c ) 3 , d ) 3.25 , e ) 3.5

Ex Output:

c