Instructions: 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'.
Input: Problem: if the selling price of 8 articles is same as the cost price of 10 articles . find the gain or loss percentage ? 
Options: a ) 25 % , b ) 45 % , c ) 35 % , d ) 65 % , e ) 55 %
Output:
a