This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
Abnormal increase in the amplitude of 'U' wave is seen with 
Select and explain. 
A. Amiodarone, B. Hypokalemia, C. Quinidine, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Ans. d (All of the above) (Ref. Harrison's Internal medicine, p. 1314; Topol cardiology Textbook, p. 158)'U' Wave# Occurs due to repolarisation of papillary muscles (Ganong Physiology p. 550, 22nd edition)# Normally upright (< 1 mm) or (< 10% of height of T wave)