The correct answer is C.
When recycling, the most important thing to do is thoroughly sort your garbage. As they say, “if you mix it together it’s garbage, if you sort it it’s a resource”. So, always be sure to throw away plastics with plastics and empty cans with empty cans. For example, putting used candy wrappers or chewing gum inside an empty can doesn’t count as recycling.

Besides sorting, it’s a good idea to thoroughly wash milk cartons, PET bottles, and empty cans before throwing them away. In other words, it’s important to always remember that these things are going to be used again.