This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Pharmacology
Which of the following is respiratory analeptic drug? 
Select and explain. 
A. Picrotoxin, B. Methylphenidate, C. Caffeine, D. Doxapram
D: Doxapram
Answer: D: Doxapram 
Explanation: ANSWER: (D) DoxapramREF: KDT 6th edition page 470CNS STIMULANT CLASSIFICATIONConvulsants: Strychnine, Picrotoxin, Bicuculline, Pentylenetetrazol (PTZ)Analeptics: DoxapramPsychostimulants: Amphetamines, Methylphenidate, Modafinil, Pemoline, Cocaine, Caffeine.Doxapram: It acts by promoting excitation of central neurones. At low doses it is more selective for the respiratory centre than other anaieptics Respiration is stimulated through carotid and aortic body chemoreceptors as well. Falling BP rises. Continuous i v infusion of doxapram has been found to abolish episode of apnoea in the premature infant not responding to Theophylline