This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urinary Tract, Subject name: Surgery
During the course of an operation on an unstable, critically ill patient, the left ureter is lacerated through 50% of its circumference. If the patient's condition is felt to be too serious to allow time for definitive repair, alternative methods of management include 
Select and explain. 
A. Ligation of the injured ureter and ipsilateral nephrostomy, B. Ipsilateral nephrectomy, C. Placement of a catheter from the distal ureter through an abdominal wall stab wound, D. Placement of a suction drain adjacent to the injury without further manipulation that might convert the partial laceration into a complete disruption
A: Ligation of the injured ureter and ipsilateral nephrostomy
Answer: A: Ligation of the injured ureter and ipsilateral nephrostomy 
Explanation: If time and the patient's condition permit, primary ureteral reconstruction should be carried out. In the middle third of the ureter, this will usually consist of ureteroureterostomy using absorbable sutures over a stent. If the injury involves the upper third, ureter pyeloplasty may be necessary. In the lower third, ureteral implantation into the bladder using a tunneling technique is preferred. If time does not permit definitive repair, suction drainage adjacent to the injured segment alone is inadequate; either ligation and nephrostomy or placement of a catheter into the proximal ureter is an acceptable alternative that would allow reconstruction to be performed later. The creation of a watertight seal is difficult and nephrectomy may be required if the injury occurs during a procedure in which a vascular prosthesis is being implanted (e.g., an aortic reconstructive procedure) and contamination of the foreign body by urine must be avoided.