**Core Concept**
Acute urinary retention in a male child can be caused by several factors, including anatomical and functional abnormalities. The condition requires prompt diagnosis and management to prevent complications such as renal impairment and sepsis.

**Why the Correct Answer is Right**
The correct answer is **B. Posterior Urethral Valve (PUV)**. PUV is a congenital anomaly that occurs in male infants, where a membrane of mucous or other tissue obstructs the posterior urethra. This obstruction prevents the normal flow of urine, leading to acute urinary retention. The mechanism involves the abnormal development of the urethral folds during fetal development, resulting in a functional obstruction.

**Why Each Wrong Option is Incorrect**
* **Option A:** Neurogenic bladder is a condition characterized by a lack of bladder control due to a neurological disorder. While it can cause urinary retention, it is less common in male children and is not the most likely cause of acute urinary retention in this population.
* **Option C:** Urinary tract infection (UTI) can cause dysuria and frequency, but it is not typically associated with acute urinary retention in male children.

**Clinical Pearl / High-Yield Fact**
Posterior urethral valves are a leading cause of obstructive uropathy in male children, and early diagnosis is crucial to prevent renal impairment and other complications.

**Correct Answer:** B. Posterior Urethral Valve (PUV)