**Core Concept:** Plethoric lung field refers to an increased lung volume due to congestion or accumulation of blood in the lungs, commonly seen in cardiovascular diseases. This can be caused by various factors including defects in heart valves, pulmonary hypertension, or left-to-right shunts.

**Why the Correct Answer is Right:** In this question, we are asked about a CHD (Congenital Heart Disease) associated with plethoric lung field. The correct option is Type B (Transposition of the Great Arteries). In this condition, the pulmonary veins drain into the systemic circulation and the systemic veins drain into the pulmonary circulation, leading to increased pulmonary blood flow and right-to-left shunting. This causes congestion in the lungs, resulting in a plethoric lung field.

**Why Each Wrong Option is Incorrect:**

A. Pulmonary Embolism: Plethoric lung field is not typically associated with pulmonary embolism, which is caused by blood clots blocking pulmonary arteries.

B. Pulmonary Hypertension: Although pulmonary hypertension can lead to plethoric lung field, it is not specific to any particular CHD.

C. Pulmonary Embolism: This option is similar to A, but with a slightly different explanation for plethoric lung field.

D. Aortic Stenosis: Plethoric lung field is not typically associated with aortic stenosis, which is a narrowing of the aortic valve.

**Clinical Pearl:** Understanding the various causes of plethoric lung field is crucial for diagnosing and managing patients with cardiovascular disorders. In clinical practice, physicians should consider the presence of plethoric lung field in the context of the patient's history, examination findings, and other relevant investigations to guide the proper diagnosis and treatment plan for the patient.