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: Medicine
All of the following feature precipitate sickling of HBS except 
Select and explain. 
A. Dehydration, B. Hypoxia, C. Infections, D. Increased PH
D: Increased PH
Answer: D: Increased PH 
Explanation: Acidosis (↓ pH) precipitate sickling.