Young Genius Student is Asking for Advice

One of our Young Genius 3rd grade students proposed the following topics for the speech he is preparing to compete with at the next middle school speech and debate tournament:
1. Why artificial intelligence might be dangerous to humanity?
2. Why 3D printing technology can be dangerous?
3. Why we should not create nanobot?
4. Does the environment truly benefit from the proliferation of electrical vehicles?

Let’s have a vote, which topic do you think is the most appropriate for a 3rd grader?