My b2evolution Version: Not Entered

Hi techies!

A while ago I enabled that "Comments are not allowed from anonymous visitors." feature to avoid spam. Now that the new anti-spam improved, I would like to disable it but I don't remember how to do that. The past 3 days I struggled to revert to the original setting (allowing anyone to post without registration) but I am not able to do that anymore.

Can anyone let me know how I disable that option?

Thank you in advance! :D

P.S. Forgot to mention version and link:

http://intromedia.ro/blog/blog1.php and the version is 4.0.3