This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S., Subject name: Medicine
Which of the following is the most likely finding in a 79-year-old woman with Parkinson's disease? 
Select and explain. 
A. constant fine tremor, B. muscle atrophy, C. akinesia, D. pupillary constriction
C: akinesia
Answer: C: akinesia 
Explanation: The characteristic triad in Parkinson's disease (Tremor, Rigidity, Akinesia) has been expanded to include Postural instability. This forms the mnemonic TRAP. Autonomic instability is also common. Findings on examination also include masklike facies, dysarthria, stooped posture, and abnormal gait.