I can't do accents on my phone. I wrote the sentence correctly without the accents and was marked wrong. I had to go to Google Translate so I could copy and paste the accents. I shouldn't have to dip into Google Translate to pass a lesson.
Google Translate agrees that cafétéria is feminine. I never trust Google Translate unconditionally so I polled some native French speakers here in Montréal. Unanimous conclusions is that cafétéria is FEMININE.