A 48 year-old male presents with history of precordial chest pain.He has BP of 80/60 mm of Hg. ECG shows wide QRS complex with no preceding P waves and a rate of 112/min. The most immediate step of this patient would be -

• A. Intravenous ligocaine
• B. DC electrical cardioversion
• C. Overdrive atrial pacing
• D. Primary percutaneous transluminal angioplasty