This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intestinal obstruction, Subject name: Surgery
Most common electrolyte imbalance that causes paralytic ileus is: 
Select and explain. 
A. Hyponatremia, B. Hypernatremia, C. Hypokalemia, D. Hyperkalemia
C: Hypokalemia
Answer: C: Hypokalemia 
Explanation: Paralytic Ileus: Common Etiologies Abdominal surgery Uremia Medications: - Anticholinergics - Opiates - Phenothiazines - Calcium channel blockers - Tricyclic antidepressants Infections: - Sepsis - Intra-abdominal abscess - Peritonitis - Pneumonia Hypothyroidism Ureteral colic Retroperitoneal hemmorrhage Spinal cord Injury Myocardical infarction Mesenteric ischemia Electrolyte abnormalities: - Hypokalemia - Hypomagnesmia - Hypermagnesemia - Hyponatremia