**Core Concept**
The question is testing the knowledge of ureteral duplication anomalies, a common congenital condition affecting the urinary tract. Ureteral duplication occurs when a single kidney develops two ureters, one of which may be ectopic and open at an abnormal site.

**Why the Correct Answer is Right**
In cases of ureteral duplication, the ectopic ureter is more likely to open into the vagina in females, but in males, it typically opens into the urethra or the prostatic urethra. The most probable site of opening of the ectopic ureter in a male child is the prostatic urethra, as it is a common location for ectopic ureters in males.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not a recognized site for the opening of an ectopic ureter in males.
* **Option B:** This option is not a typical site for the opening of an ectopic ureter in males, although it could be a possible site in females.
* **Option D:** This option is not a recognized site for the opening of an ectopic ureter in males.

**Clinical Pearl / High-Yield Fact**
In males with ureteral duplication, the ectopic ureter is more likely to open into the prostatic urethra, and this should be considered when evaluating a child with recurrent urinary tract infections or urinary incontinence.

**Correct Answer: C. Prostatic urethra**