**Core Concept**
Right atrial isomerization syndrome, also known as right atrial isomerism, is a rare congenital anomaly characterized by bilateral right-sided atrial appendages. This condition often presents with complex cardiac and extracardiac abnormalities, including abnormal situs of the abdominal organs.

**Why the Correct Answer is Right**
The correct answer, **B. Always associated with dextrocardia**, is incorrect because right atrial isomerism can be associated with either situs solitus, situs inversus, or a combination of both. Dextrocardia is not a universal feature of this condition, and it can be present in a minority of cases. The presence of bilateral right atria is a hallmark of this syndrome, which often involves other cardiac abnormalities such as common atrioventricular valve and abnormal pulmonary venous return.

**Why Each Wrong Option is Incorrect**
**Option A:** Absence of the spleen (asplenia) is actually more commonly associated with left atrial isomerism, not right atrial isomerism. In right atrial isomerism, the spleen may be present and normal.
**Option C:** Cyanosis can be present in right atrial isomerism due to the abnormal pulmonary venous return and increased pulmonary vascular resistance. Therefore, this option is incorrect.
**Option D:** Bilateral right atria are indeed a characteristic feature of right atrial isomerism, making this option incorrect.

**Clinical Pearl / High-Yield Fact**
It is essential to recognize that right atrial isomerism is a part of the broader spectrum of heterotaxy syndromes, which involve complex congenital anomalies of the heart and abdominal organs. A high index of suspicion and detailed evaluation are necessary to diagnose this condition accurately.

**✓ Correct Answer: B. Always associated with dextrocardia**