Final answer:
Adenosine is the appropriate treatment for narrow QRS complex tachycardia with strange or absent P waves.
Step-by-step explanation:
In the treatment of narrow QRS complex tachycardia with strange or absent P waves, the correct option is a) Adenosine. Adenosine is used to treat supraventricular tachycardias, including those with abnormal or absent P waves. It helps restore normal sinus rhythm by blocking the conduction through the atrioventricular node.