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 searchlight on top of the watchtower makes 2 revolutions per minute . what is the probability that a man appearing near the tower will stay in the dark for at least 5 seconds ? 
Options: a ) 5 / 6 , b ) 5 / 12 , c ) 7 / 12 , d ) 11 / 12 , e ) 11 / 15

Ex Output:
a


Ex Input:
Problem: a can do a piece of work 60 days . b can do work in 20 days . in how many days they will complete the work together ? 
Options: a ) 12 days , b ) 16 days , c ) 15 days , d ) 17 days , e ) 18 days

Ex Output:
c


Ex Input:
Problem: find the length of the wire required to go 13 times round a square field containing 24336 m 2 . 
Options: a ) 15840 , b ) 3388 , c ) 2667 , d ) 8112 , e ) 66711

Ex Output:

d