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: Surgery
Which among the following is the MOST common cause of superficial thrombophlebitis? 
Select and explain. 
A. Trauma, B. Infection, C. Varicosities, D. Intravenous infusion
D: Intravenous infusion
Answer: D: Intravenous infusion 
Explanation: Superficial thrombophlebitis is a disorder of superficial veins characterized by aseptic local inflammation. In the upper extremity it is caused by IV infusion of acidic fluid or prolonged cannulation. Thrombophlebitis migrans or recurrent superficial thrombophlebitis is associated with malignant visceral tumors, systemic collagen vascular disease and blood dyscrasias.The deep veins and visceral veins may be involved. Ref: Essentials of Surgery: Scientific Principles and Practice edited by Lazar J. Greenfield, page 690.