Task: Question Answering
Input (English): Problem: a retailer bought a machine at a wholesale price of $ 80 and later on sold it after a 20 % discount of the retail price . if the retailer made a profit equivalent to 20 % of the wholesale price , what is the retail price of the machine ? 
Options: a ) $ 80 , b ) $ 100 , c ) $ 120 , d ) 135 , e ) 160
Output (English): c