**Core Concept**
Bronchiolitis obliterans (BO) is a rare but severe lung disorder characterized by inflammation and scarring of the small airways, leading to chronic respiratory symptoms. It is often associated with previous lung injury or infection, and can occur in both children and adults.

**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology of bronchiolitis obliterans without cyanosis. BO is typically characterized by a restrictive lung pattern and impaired gas exchange, which can lead to chronic respiratory symptoms such as cough, wheezing, and shortness of breath. However, in some cases, patients with BO may not exhibit cyanosis, despite significant lung impairment. This is because the disease often affects the small airways, leading to a more gradual decline in lung function and a lower likelihood of significant hypoxemia.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because bronchiolitis obliterans is often associated with a restrictive lung pattern, which can lead to significant hypoxemia and cyanosis. While some patients may not exhibit cyanosis, this is not a defining characteristic of the disease.

**Option B:** This option is incorrect because bronchiolitis obliterans is not typically characterized by an obstructive lung pattern. While some patients may exhibit wheezing or other obstructive symptoms, the underlying pathophysiology of the disease is more closely related to inflammation and scarring of the small airways.

**Option C:** This option is incorrect because bronchiolitis obliterans is not typically associated with a normal chest radiograph. In fact, chest imaging is often abnormal in patients with BO, showing signs of lung scarring or inflammation.

**Option D:** This option is incorrect because bronchiolitis obliterans is not typically a self-limiting condition. While some patients may experience a gradual decline in lung function, BO is often a chronic and progressive disease that requires ongoing medical management.

**Clinical Pearl / High-Yield Fact**
One key feature of bronchiolitis obliterans is its association with previous lung injury or infection. This can include conditions such as pneumonia, aspiration, or inhalation injury. Recognizing this association is critical for making an accurate diagnosis and developing an effective treatment plan.

**Correct Answer:** B.