**Core Concept**
Primary tuberculosis (TB) is the initial infection with Mycobacterium tuberculosis, which usually occurs in the lungs. It is characterized by the formation of a primary complex, consisting of a Ghon focus (a granulomatous lesion) and a hilar lymphadenitis.

**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of primary TB. The primary complex is formed due to the body's immune response to the tubercle bacillus. This complex is composed of a Ghon focus, which is a granulomatous lesion in the lung, and a hilar lymphadenitis, which is inflammation of the lymph nodes in the hilar region. The Ghon focus is a characteristic feature of primary TB and is formed as a result of the tubercle bacillus infecting the lung tissue.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not related to primary TB. The other options are incorrect because they are not characteristic features of primary TB.

**Clinical Pearl / High-Yield Fact**
A key feature of primary TB is the formation of a Ghon focus, which is a granulomatous lesion in the lung. This lesion is a result of the body's immune response to the tubercle bacillus and is a characteristic feature of primary TB.

**Correct Answer: Not Provided**
Please provide the remaining options (A, B, C, D) for a complete explanation.