Pasteurization is the process of heating milk to a high enough temperature for a long enough time to kill illness-causing germs.
Candling is a method used to observe the growth and development of an embryo inside an egg which uses a bright light source behind the egg to show details through the shell. It is so called because the original sources of light used were candles.
Due to these definitions, I’d say #4. Pasteurization makes milk safe to consume and making sure an egg is underutilized with candling can also make sure of that.