Nu Html Checker

Hello

I just wanted to ask:

Does Nu Html Checker check for all WCAG 2.0 Level A, AA, and AAA issues? Or is it just for Level AA? 
The reason I’m asking is because I doing a project using three accessibility checkers and only analyzing Level A issues on several website homepages. The two other accessibility checkers all have WCAG 2.0 A, AA, and AAA levels to choose from, which is nice. Please let me know what WCAG 2.0 levels your checker uses when you have a minute.

Best,

Michael Sabbia

Sent from Mail for Windows 10