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: Medicine
A housewife ingests a rodenticide white powder accidentally. She is brought to hospital where the examination shows generalized, flaccid paralysis and an irregular pulse. ECG shows multiple ventricular ectopics, generalized changes with ST. Serum potassium is 2.5 mE/1. The most likely ingested poison is - 
Select and explain. 
A. Barium carbonate, B. Superwarfarins, C. Zinc phosphide, D. Aluminium phosphide
A: Barium carbonate
Answer: A: Barium carbonate 
Explanation: None