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 12 men do a work in 80 days , in how many days will 16 men do it ? 
Options: a ) 22 , b ) 87 , c ) 77 , d ) 60 , e ) 85

Ex Output:
d


Ex Input:
Problem: if 20 typists can type 50 letters in 30 minutes , then how many letters will 40 typists working at the same rate complete in 1 hour ? 
Options: a ) 400 , b ) 500 , c ) 350 , d ) 250 , e ) 200

Ex Output:
a


Ex Input:
Problem: a train of length 250 m crosses a bridge of length 150 m in 20 seconds . what is the speed of train ? 
Options: a ) 33 , b ) 27 , c ) 25 , d ) 22 , e ) 72

Ex Output:

e