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: alex takes a loan of $ 4,000 to buy a used truck at the rate of 6 % simple interest . calculate the annual interest to be paid for the loan amount . 
Options: a ) 680 , b ) 700 , c ) 240 , d ) 620 , e ) 260
Example Output: c

Example Input: Problem: shawn invested one half of his savings in a bond that paid simple interest for 2 years and received $ 550 as interest . he invested the remaining in a bond that paid compound interest , interest being compounded annually , for the same 2 years at the same rate of interest and received $ 605 as interest . what was the value of his total savings before investing in these two bonds ? 
Options: a ) $ 2,750 , b ) $ 5,500 , c ) $ 11,000 , d ) $ 22,000 , e ) $ 44,000
Example Output: a

Example Input: Problem: find the 25 % of rs . 500 . 
Options: a ) s . 50 , b ) s . 70 , c ) s . 100 , d ) s . 125 , e ) s . 60
Example Output:
d