**Core Concept**
Kartagener's syndrome is a rare genetic disorder characterized by the triad of primary ciliary dyskinesia (PCD), chronic sinusitis, and situs inversus. It results from mutations in genes encoding for dynein arms, which are essential for the movement of cilia.

**Why the Correct Answer is Right**
Kartagener's syndrome is caused by defects in the dynein arms of cilia, leading to impaired ciliary function. This results in the accumulation of mucus in the respiratory tract, causing chronic sinusitis and recurrent respiratory infections. The situs inversus occurs due to the abnormal movement of embryonic cells during embryogenesis, leading to an inverted position of the abdominal and thoracic organs.

**Why Each Wrong Option is Incorrect**
* **Option A:** Bronchiectasis is a common complication of Kartagener's syndrome due to recurrent infections and impaired clearance of mucus. Therefore, it is a characteristic feature of the syndrome.
* **Option B:** Chronic sinusitis is a hallmark of Kartagener's syndrome, resulting from impaired ciliary function and mucus accumulation in the sinuses.
* **Option C:** Situs inversus is a key feature of Kartagener's syndrome, resulting from abnormal embryonic cell movement and ciliary dysfunction.

**Clinical Pearl / High-Yield Fact**
Kartagener's syndrome can be diagnosed using nasal nitric oxide measurement, which is decreased in patients with PCD. This test is a useful diagnostic tool, especially in patients with a family history of the syndrome.

**Correct Answer: D.**