Task: Question Answering
Input (English): Problem: a certain drink of type a is prepared by mixing 4 parts milk with 3 parts fruit juice . another drink of type b is prepared by mixing 4 parts of fruit juice and 3 parts of milk . how many liters of fruit juice must be added to 84 liters of drink a to convert it to drink b ? 
Options: a ) 24 , b ) 28 , c ) 32 , d ) 36 , e ) 40
Output (English): b