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
Involuntary contraction of a single motor unit is known as 
Select and explain. 
A. Fibrillation, B. Fasciculation, C. Tics, D. Spasm
B: Fasciculation
Answer: B: Fasciculation 
Explanation: Fasciculation : It is involuntary contraction of a single motor unit. It is visible grossly.
Fibrillation : It is spontaneous, repititive contraction of a single muscle fibre. It is not visible grossly.