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: mariah has decided to hire three workers . to determine whom she will hire , she has selected a group of 12 candidates . she plans to have one working interview with 3 of the 12 candidates every day to see how well they work together . how many days will it take her to have working interviews with all the different combinations of job candidates ? 
Options: a ) 720 , b ) 120 , c ) 300 , d ) 30 , e ) 333

Ex Output:
c


Ex Input:
Problem: a 21 cm long wire is to be cut into two pieces so that one piece will be 2 / 5 th of the other , how many centimeters will the shorter piece be ? 
Options: a ) 12 , b ) 6 , c ) 88 , d ) 77 , e ) 14

Ex Output:
b


Ex Input:
Problem: 20 men do a work in 20 days . how many men are needed to finish the work in 4 days ? 
Options: a ) 50 , b ) 20 , c ) 30 , d ) 100 , e ) 15

Ex Output:

d