Number two shows self checks
Answer:
1. X is an apple is necessary condition for X has a sour taste. If X is an apple, then it should have a sour taste.
2. X is being smaller than 100 is a sufficient condition for X is being smaller than 21. If X < 21, then X <100
3. X is gambling in a legal casino is both a necessary and sufficient condition for X is 18 years old or above. It is a must for X to gamble when X is 18 years old. If X is not gambling, X is not 18 years old.
4. Aurora is a parent is a necessary condition for Aurora has a daughter-in-law. If Aurora is a parent, so that she can have a daughter-in-law.
5. Philip is a vegetarian is sufficient for Philip loves tofu. If Philip doesn't love tofu, it is not enough for him to be a vegetarian.
Hope this help you.
I'd say it's the baseball
I believe the last option is correct
