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: Pharmacology
Most common side effect of DH Ps calcium channe blockers is - 
Select and explain. 
A. Headache, B. Constipation, C. Diarrhoea, D. Muscle cramps
A: Headache
Answer: A: Headache 
Explanation: Ans. is `a' i.e., Headache o The most common side effects caused by the Ca" channel antagonists, paicularly the dihydropyridines, are due to excessive vasodilator. Symptoms include dizziness, hypotension, headache, flushing, digital dysesthesia, and nausea.