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
A 75-year-old patient suffering from congestive hea failure accidentally ingests a toxic dose of digoxin. Clinical consequences due to the toxic effects of cardiac glycosides are likely to include 
Select and explain. 
A. Seizures, B. Visual disturbances, C. Bicarbonaturia, D. Intermittent claudication
B: Visual disturbances
Answer: B: Visual disturbances 
Explanation: Digoxin adverse effects- CNS effects, visual manifestations, arrhythmia and GI symptoms. Digoxin inhibits Na+/K+-ATPase and impairs the uptake of K+ by skeletal muscle, such that digoxin overdose predictably results in hyperkalemia.