**Core Concept**
Anorectal anomalies are congenital malformations of the anorectal region, often presenting as a spectrum of disorders ranging from minor to complex malformations. These anomalies can be associated with other congenital anomalies due to their shared embryological origins.

**Why the Correct Answer is Right**
The correct answer is associated with cardiac anomalies due to their shared embryological origins from the mesoderm. The development of the anorectal region and heart is closely linked in the embryological process. Abnormalities in the development of the cloaca, a structure that eventually gives rise to the anorectal region and the lower part of the urinary tract, can lead to both anorectal and cardiac malformations. This association is most commonly seen in VACTERL association (Vertebral defects, Anal atresia, Cardiac defects, Tracheo-Esophageal fistula, Renal anomalies, and Limb abnormalities).

**Why Each Wrong Option is Incorrect**
**Option B:** Duodenal atresia is a congenital anomaly of the small intestine and is not typically associated with anorectal anomalies. While both are congenital malformations, they arise from different embryological structures.

**Option C:** CMS (Congenital Muscular Sphincter) abnormalities are not a commonly recognized term in the context of anorectal anomalies. While muscular anomalies can be seen in some cases of anorectal malformations, this option is too vague and does not accurately represent the typical associations.

**Option D:** Abdominal wall defects, such as gastroschisis or omphalocele, are congenital anomalies of the abdominal wall and are not directly associated with anorectal anomalies.

**Clinical Pearl / High-Yield Fact**
In patients with anorectal anomalies, it is essential to perform a thorough evaluation for associated congenital anomalies, particularly cardiac malformations, as these can significantly impact the patient's prognosis and management.

**✓ Correct Answer: A. Cardiac anomalies**