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: you hold some gold in a vault as an investment . over the past year the price of gold increases by 40 % . in order to keep your gold in the vault , you must pay 5 % of the total value of the gold per year . what percentage has the value of your holdings changed by over the past year . 
Options: a ) 35 % , b ) 33 % , c ) 36 % , d ) 38 % , e ) 40 %
Example Output: b

Example Input: Problem: a cycle is bought for rs . 1120 and sold for rs . 1200 , find the gain percent ? 
Options: a ) 7 % , b ) 2 % , c ) 6 % , d ) 1 % , e ) 8 %
Example Output: a

Example Input: Problem: the true discount on a bill due 9 months hence at 16 % per annum is rs . 180 . the amount of the bill is 
Options: a ) 1200 , b ) 1764 , c ) 1680 , d ) 1354 , e ) none of these
Example Output:
c