This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Pharmacology
Which among the following is the best inotrope drug for use in right hea failure? 
Select and explain. 
A. Dobutamine, B. Digoxin, C. Dopamine, D. Milrinone
D: Milrinone
Answer: D: Milrinone 
Explanation: Drugs with beta-adrenergic and dopaminergic D1 agonist have a positive inotropic effect. Milrinone is a phosphodiesterase 3 inhibitor that works to increase the hea's contractility and decrease pulmonary vascular resistance. (REF. Essentials of medical pharmacology KD TRIPATHI 8th Edition)