Which of the following statements regarding smoke control systems is MOST accurate?

Which of the following statements regarding smoke control systems is MOST accurate?
 
  A) Model building codes require special mechanical smoke removal provisions from the floor of origin.
  B) Shaft construction, sealing of floor penetrations, and automatic sprinklers are considered adequate to control smoke movement in a building.
  C) Building codes require smoke proof exit enclosures in all stairs serving floors 50 feet (15.2 m) or higher.
  D) Building codes require all entrances to stairwells in a high-rise be through a pressurized vestibule.