They are both cities and suburbs. They have legal status of cities while being satellites (suburbs) of a larger city in a metropolitan area, which is what the quiz is about.
There is no legal designation for a suburb, planning-wise you have either a city or a census designated place.
Check this map:(https://upload.wikimedia.org/wikipedia/commons/6/6c/CBSA_WallMap_Jul2023.pdf) of metropolitan statistical areas if you want to understand my criteria for this quiz.
Check this map:(https://upload.wikimedia.org/wikipedia/commons/6/6c/CBSA_WallMap_Jul2023.pdf) of metropolitan statistical areas if you want to understand my criteria for this quiz.