Seven buildings are located in an urban development.
Three of the buildings are residential; the other four are commercial.
Each of the residential buildings is made of either brick or wood.
Each of the commercial buildings is made of either wood, concrete, brick, or steel.
All of the residential buildings and all of the brick buildings have fire escapes, but no other buildings do.
Exactly four of the buildings have fire escapes.
If there are exactly three brick buildings and one steel building, then any of the following can be true EXCEPT: