Setting up No-Bot Registration
For most people the basic (or default) settings will work fine. If the problem with fake accounts is not solved completely you can fine-tune No-Bot Registration to your needs.
You'll find all settings for No-Bot Registration in your WordPress dashboard in the Tools menu.
No-Bot Registration tries to not hinder your visitors with annoying security features by simply imposing certain rules or limitations on them. There are no captchas to interpret, no riddles to solve. Just simple common sense measures that every real human can understand.
The one exception to this is the security question, which you as the website owner can configure. But also for this, simple questions with simple answers often do the trick.