Think about the history of Halloween. Which of these happened after World War II?

The popular Halloween tradition of "guising" saw children perform a song for treats.
Sugar was rationed, and people couldn't give out sweet treats to children.
People celebrated "mumming" by going door to door and asking for food and drinks.
Candy companies advertised Halloween to boost sales for wrapped candies.

Candy companies advertising Halloween to boost sales for wrapped candies happened after World War II.