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: Physiology
Inability to perform rapid alternating movement is - 
Select and explain. 
A. Past-pointing, B. Dysdiadochokinesia, C. Dysmetria, D. None
B: Dysdiadochokinesia
Answer: B: Dysdiadochokinesia 
Explanation: Dysdiadochokinesia: Inability to perform rhythmic, rapidly alternating movements like pronation and supination.
Past-pointing (overshoot): Failure to stop a movement at an appropriate time.
Dysmetria: Errors in the range and force of movement, which may be due to past-pointing.