In this task, you need to answer the given multiple-choice question on the gain. Gain is the value by which to multiply the input. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

Ex Input:
Problem: a shopkeeper has 100 kg of apples . he sells 50 % of these at 25 % profit and remaining 50 % at 30 % profit . find his % profit on total . 
Options: a ) 27.5 % , b ) 25.6 % , c ) 31.5 % , d ) 35.9 % , e ) 29.5 %

Ex Output:
a


Ex Input:
Problem: the cost price of a radio is rs . 2550 and it was sold for rs . 2130 , find the loss % ? 
Options: a ) 18 , b ) 10 , c ) 15 , d ) 66 , e ) 41

Ex Output:
c


Ex Input:
Problem: in a certain math department , students are required to enroll in either calculus or trigonometry , each of which is offered in beginner and advanced courses . the number of students enrolled in trigonometry is 50 % greater than the number of students enrolled in calculus , and 80 % of calculus students are enrolled in the beginner course . if 4 / 5 of students are in the beginner courses , and one student is selected at random , what is the probability that an advanced trigonometry student is selected ? 
Options: a ) 8 % , b ) 12 % , c ) 16 % , d ) 20 % , e ) 24 %

Ex Output:

b