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: Dental
Saliva which is formed in salivary glands, when passes from salivary gland to duct orifices, it undergoes numerous ion exchanges and as a result
saliva become ____________ as compared to plasma: 
Select and explain. 
A. Hypertonic sometimes, B. Hypotonic, C. Isotonic, D. Hypertonic always
B: Hypotonic
Answer: B: Hypotonic 
Explanation: None