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
Features of parkinsons disease-a) Decreased Blinkingb) Spasticityc) On-off phenomenond) Objective ↓ muscle powere) Tremor 
Select and explain. 
A. acd, B. bde, C. cde, D. ace
D: ace
Answer: D: ace 
Explanation: None