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
Which of the following conditions increases the risk of digoxin toxicity ? 
Select and explain. 
A. Administration of quinidine, B. Hyperkalemia, C. Hypermagnesemia, D. Hypocalcemia
A: Administration of quinidine
Answer: A: Administration of quinidine 
Explanation: None