Task: Question Answering
Input (English): Problem: a grocer purchased a quantity of bananas at 3 pounds for $ 0.50 and sold the entire quantity at 4 pounds for $ 1.00 . how many pounds did the grocer purchase if the profit from selling the bananas was $ 7.00 ? 
Options: a ) 40 , b ) 84 , c ) 90 , d ) 120 , e ) 240
Output (English): b