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
The effect which is seen due to decrease in serum calcium concentration is 
Select and explain. 
A. Relaxation of muscle, B. Excitability of the muscle, C. Increase the renal absorption, D. Depression of Nervous system
B: Excitability of the muscle
Answer: B: Excitability of the muscle 
Explanation: None