I put "in the center of town" here, it seems a reasonable interpretation to me but gets marked incorrect. Maybe too colloquial?
I would report it.
Yes, report it. That is much better than center of the city. Do they accept "downtown," which would also be possible, though a bit different?
Why not "Anna is renting a apartment in the centre of the city"?
You should use the article an before words that start with a vowel sound.
I got all English and said a flat in the middle of town. Which is what I would say even if it was in a city. Very annoying
I think "in the middle of the city would also work