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'.

Example Input: Problem: a 6 litre sol is 30 % alcohol . how many litres of pure alcohol must be added to produce a sol that is 50 % alcohol ? 
Options: a ) a . 0.6 , b ) b . 1 , c ) c . 2.1 , d ) d . 3 , e ) e . 2.4
Example Output: e

Example Input: Problem: a man ' s speed with the current is 12 km / hr and the speed of the current is 2 km / hr . the man ' s speed against the current is 
Options: a ) 8 , b ) 10 , c ) 11 , d ) 12 , e ) 13
Example Output: a

Example Input: Problem: a technician makes a round - trip to and from a certain service center by the same route . if the technician completes the drive to the center and then completes 10 percent of the drive from the center , what percent of the round - trip has the technician completed ? 
Options: a ) 5 % , b ) 10 % , c ) 25 % , d ) 40 % , e ) 55 %
Example Output:
e

