Ava loves all of the Disney princesses, but her favorite is Elsa, from the movie Frozen. She thinks everyone should love Elsa, and she just can't let it go! Ava wants to survey a large sample of young girls and ask them to vote for their favorite princess from the following list:
Ava believes that $40\%$ of young girls would choose Elsa. What type of significance test should she conduct in order to test this theory?