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: Radiology
A dense persistent nephrogram may be seen in all of the following except – 
Select and explain. 
A. Acute ureteral obstruction, B. Systemic hypertension, C. Severe hydronephrosis, D. Dehydration
B: Systemic hypertension
Answer: B: Systemic hypertension 
Explanation: Hypotension causes persistent dense nephrogram (not hypertension).