Why isn't it weißer Tee? (Like "Es ist ein roter Apfel")
Accusative Vs. Nominative?
I'm by no means an expert but I had a look at Christian's second link and as this is in the accusative form the tables show that weißen should be used as weißer is nominative (when there is no article)
Why would it be "weissen" rather than "weisse"? Wouldn't "weissen" be plural; why isn't "weisse" sufficient to show the gender of "Tee"?
It's more complex than you think.
how come in one of the options it says "Die Frau trinkt schwarze Tee." and not "schwarzen Tee" ?
edit: Never mind. I misread your comment. "Die Frau trinkt schwarze Tee" is wrong and "Die Frau trinkt schwarzen Tee" is correct.