My grandfather was a real trader . Yeah , typical Dutch , haha . He knew how to make money in almost anything . One of the things he would do , he would stop by the side of the road , pick up empty soda and beer bottles , return them to the store and collect the deposit . Every now and then , he would go to the dump and spent half a day , walking around on it , looking at what people had thrown out . Anything he thought might still have some value , he would bring home , polish it up , or restore it and hold a barn - sale .

Generate a question about the above context.
How was the grandfather able to cash in empty cans ?
Available choices: [I] He polished the cans first .. [II] He gave them out to people .. [III] The store collected the metal .. [IV] He sold them to others ..