Final answer:
The least secure Internet Explorer zone is the Internet zone, while the restricted sites zone has the highest security settings.
Step-by-step explanation:
The least secure Internet Explorer zone is the Internet zone. This zone contains websites that are not on your trusted sites list, and by default, it has more relaxed security settings compared to other zones.
The local intranet zone and the trusted sites zone have higher security levels. The local intranet zone is for websites on your local network, while the trusted sites zone is for websites that you trust and want to give additional permissions to.
The restricted sites zone has the highest security settings and is intended for websites that you do not trust or consider to be potentially harmful.