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 hall 36 m long and 15 m broad is to be paved with stones , each measuring 8 dm by 5 dm . the number of stones required is : 
Options: a ) 180 , b ) 1800 , c ) 18 , d ) 18000 , e ) 1350

Ex Output:
e


Ex Input:
Problem: twelve machines , each working at the same constant rate , together can complete a certain job in 6 days . how many additional machines , each working at the same constant rate , will be needed to complete the job in 3 days ? 
Options: a ) 14 , b ) 12 , c ) 15 , d ) 16 , e ) 18

Ex Output:
b


Ex Input:
Problem: 15 men take 21 days of 8 hrs . each to do a piece of work . how many days of 3 hrs . each would it take for 21 women if 3 women do as much work as 2 men ? 
Options: a ) 60 , b ) 20 , c ) 19 , d ) 29 , e ) 39

Ex Output:

a