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: the effective annual rate of interest corresponding to a nominal rate of 6 % per annum payable half - yearly is : 
Options: a ) 6.09 % , b ) 6.08 % , c ) 6.1 % , d ) 6.07 % , e ) 6.05 %
Example Output: a

Example Input: Problem: john and jane went out for a dinner and they ordered the same dish . both used a 10 % discount coupon . john paid a 15 % tip over the original price of the dish , while jane paid the tip over the discounted price for the coupon . if john paid $ 0.63 more than jane , what was the original price of the dish ? 
Options: a ) 24 , b ) 34.8 , c ) 37.8 , d ) 42 , e ) 84
Example Output: d

Example Input: Problem: consider a lady took a loan from a bank at the rate of 12 % p . a . simple interest . after 3 years she had to pay rs . 9900 interest only for the period . the principal amount borrowed by her was 
Options: a ) rs . 2000 , b ) rs . 27500 , c ) rs . 15000 , d ) rs . 20000 , e ) none of these
Example Output:
b