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
Reduction in flow of saliva is not generally seen in: 
Select and explain. 
A. Elderly diabetics, B. b)Patient undergoing radiation therapy, C. Patients suffering from parkinsonism, D. Patients on phenothiazine drugs
C: Patients suffering from parkinsonism
Answer: C: Patients suffering from parkinsonism 
Explanation: None