"The article 'the'."
Translation:Το άρθρο το.
I think he's saying that some answers require 'η', while others require 'το', while all the other articles are ignored altogether. I know you haven't specifically taught all of them up to this point (even though a few have appeared in lessons), but is it possible to make them all correct? Otherwise we'll just be trying to guess which article you mean this time.
Also, I put 'η' and I got it wrong, so it's not accepting that either.