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: 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


Ex Input:
Problem: a doctor prescribed 18 cubic centimeters of a certain drug to a patient whose body weight was 105 pounds . if the typical dosage is 2 cubic centimeters per 15 pounds of the body weight , by what percent was the prescribed dosage greater than the typical dosage ? 
Options: a ) 8 % , b ) 9 % , c ) 11 % , d ) 12.5 % , e ) 14.28 %

Ex Output:
e


Ex Input:
Problem: in a certain parking lot , 10 % of the cars are towed for parking illegally . however 80 % of the cars which are parked illegally are not towed . what percentage of cars in the parking lot are parked illegally ? 
Options: a ) 30 % , b ) 40 % , c ) 50 % , d ) 60 % , e ) 70 %

Ex Output:

c