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: Pharmacology
[{'content': 'All of the following are ECG changes seen in Digoxin toxicity except \nSelect and explain. \nA. QT shortening, B. PR shortening, C. ST depression, D. T wave inversion', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Digoxin is a AV Nodal blocker and hence it leads to PR prolongation not shortening.', 'role': 'assistant'}]