Farrah Abraham -- Graduates Magnum Cum Laude From Booze School

Farrah Abraham might have two D's on her chest, but she got all A's in her drunk classes -- the "Teen Mom" passed her alcohol ed classes with flying colors.

As TMZ previously reported ... the anusly-gifted porn star copped a plea deal with prosecutors earlier this month -- pleading guilty to DUI. She got 6 months probation and was ordered to complete an alcohol education course.

The "Backdoor Teen Mom" took her punishment like a man. We're told she was on her "best behavior" in booze school.

Farrah took the classes in Texas (where she lives), rather than Nebraska (where she was arrested) and even got a diploma! Well, really it's just a certificate of completion.

Champagne anyone?