This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
Cause of odema 
Select and explain. 
A. Decreased plasma protein concentration, B. Increased lymph flow, C. Increased ECF, D. Increased plasma proteins concentration
A: Decreased plasma protein concentration
Answer: A: Decreased plasma protein concentration 
Explanation: Ref.robbins 8/e 112; 7/e 120- 121;9/e p114 Capillary blood contains a decreased quantity of colloids (protein-white circles) due to either decreased hepatic synthesis of these proteins or increased protein loss through the kidney or gastrointestinal tract. ... With decreased production of albumin the plasma colloidal osmotic pressure decreases and edema occurs.