Task: Question Answering
Input (English): Problem: a certain rectangular crate measures 6 feet by 8 feet by 10 feet . a cylindrical gas tank is to be made for shipment in the crate and will stand upright when the crate is placed on one of its six faces . what should the radius of the tank be if it is to be of the largest possible volume ? 
Options: a ) 4 , b ) 4 , c ) 6 , d ) 8 , e ) 10
Output (English): b