**Core Concept**
Anorectal agenesis with a rectourethral fistula is a congenital anomaly resulting from a failed development of the cloaca and urogenital sinus. The cloaca is a common embryonic chamber that separates into the anorectal canal and urogenital sinus during embryogenesis.

**Why the Correct Answer is Right**
The correct answer involves the failure of the cloaca to properly differentiate, leading to a persistent communication between the rectum and the urogenital sinus. This defect occurs due to the abnormal migration of the cloacal membrane. The cloacal membrane is made of ectodermal and endodermal layers and is a critical structure for the separation of the anorectal and urogenital systems.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not directly related to the embryologic development of the anorectal and urogenital systems.
* **Option B:** Although neural crest cells contribute to the development of the enteric nervous system, they are not directly responsible for the formation of the anorectal canal or urogenital sinus.
* **Option D:** This option is not a known embryologic cause of anorectal agenesis with a rectourethral fistula.

**Clinical Pearl / High-Yield Fact**
The high incidence of anorectal malformations with associated genitourinary anomalies highlights the importance of a thorough genitourinary examination in infants with anorectal agenesis.

**Correct Answer:** C.