Task: Question Answering
Input (English): Problem: by selling an article at rs . 800 , a shopkeeper makes a profit of 25 % . at what price should he sell the article so as to make a loss of 50 % ? 
Options: a ) s . 429 , b ) s . 480 , c ) s . 320 , d ) s . 128 , e ) s . 419
Output (English): c