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: Pathology
Edema may be caused by any of the following, EXCEPT: 
Select and explain. 
A. An increase in the plasma protein concentration, B. An increase in the capillary hydrostatic pressure, C. An increase in the capillary permeability, D. Lymphatic obstruction
A: An increase in the plasma protein concentration
Answer: A: An increase in the plasma protein concentration 
Explanation: Oedema is caused by mechanisms that interfere with normal fluid balance of plasma, interstitial fluid and lymph flow.
The following mechanisms may be operating singly or in combination to produce oedema:

Decreased plasma oncotic pressure.
Increased capillary hydrostatic pressure.
Lymphatic obstruction.
Tissue factors (increased oncotic pressure of interstitial fluid, and decreased tissue tension).
Increased capillary permeability.
Sodium and water retention.

Mohan H. Textbook of pathology. Jaypee Brothers Medical Publishers; 2015. Edition 7. Page 80