This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
Intrapleural Pressure during forceful expiration is 
Select and explain. 
A. - 20 mm Hg, B. + 5 mm Hg, C. - 5 mm Hg, D. + 20 mm Hg
D: + 20 mm Hg
Answer: D: + 20 mm Hg 
Explanation: Intrapleural Pressure: (ITP) / Intrathoracic Pressure
It is the pressure within pleural space (space between visceral and parietal pleura)

At beginning of inspiration = -2.5 mm Hg / - 5 cm H2O
At end of inspiration = - 6.0 mm Hg / - 10 cm H2O
At end of expiration = - 2.5 mm Hg / - 5 cm H2O
Forceful inspiration = - 20 mm Hg
Forceful expiration = + 20 to  + 30 mm Hg