Which US city is served by the BART public transport system?
Correct answer: San Francisco

Mars V
That’s because it is an acronym, not an abbreviation.

SQinfoNUTS
I live in the Philadelphia Pennsylvania area. A good friend went to San Francisco some years ago and I was astounded that not only did the trains run on time they were clean and there was no threat of murder robbery or dismemberment while riding the trains.