They are asking for the translation 'a tea', but in English that is not grammatically correct, it translates to 'a cup of tea' because tea is not a count-able noun. Some other uncount-ables are water (a glass of), bread (a loaf of), and soup (a bowl of). The idea is that you can't count the particles of soup, you can only measure it, so it must be measured via the vessel it is in, ie. cup or bowl. Also, "tee" means the little balancer under a golf ball when you are playing golf, and while that is countable, it's the wrong word, not sure if that was a typo or not. You can't say "the tea" in this case, because in Romanian, 'tea' is 'ceai', and 'the tea' is 'ceaiul'. So it wasn't asking for you to translate it to 'the tea', which is why that answer would not be accepted.
I hope that made sense!
"A tea" is gramatically correct in English, just as "a coffee", "a beer", "a soda", "a Coke", "a whiskey", etc. It may feel less natural to people who are not often around tea drinkers. Thus it surely sounds more natural to native English speakers from the UK or India than to Americans.
IMHO both "a tea" and "a cup of tea" should be acceptable for this one. I can see reasons for some English speakers to disagree with each one on different grounds, so whichever they choose for the default correct English people will complain.
That does make a lot of sense, but in this regard i feel that most people would just take out the particle... instead of adding additional words that might change the meaning?
I dont know romanian >< so i cant say for certain but adding a measure word in front in English drastically changes the meaning.
Ex A cup of tea vs A teaspoon of tea vs A truckload of tea