**Question:** Rhinoscleromatis is caused by:

**Core Concept:** Rhinoscleroma is an infectious disease caused by bacteria, primarily affecting the respiratory and gastrointestinal tracts. The three main forms of the disease are rhinoscleroma, kala-azar, and tubero-retrobulbar.

**Why the Correct Answer is Right:** Rhinoscleroma is caused by the bacterium **Klebsiella rhinoscleromatis**. This bacterium primarily infects the nasopharynx leading to the disease's characteristic granulomatous inflammation.

**Why Each Wrong Option is Incorrect:**

A. **Klebsiella pneumoniae:** This bacterium primarily causes pneumonia and meningitis, not rhinoscleroma.
B. **Mycobacterium tuberculosis:** Mycobacteria are responsible for tuberculosis, not rhinoscleroma.
C. **Corynebacterium:** Corynebacteria are related to diphtheria, not rhinoscleroma.

**Clinical Pearl / High-Yield Fact:** To avoid confusion with other infections, remember the acronym "K.R.H." for Klebsiella rhinoscleromatis, the bacterium causing rhinoscleroma.

**Correct Answer:** .

**Correct Answer: D.** Klebsiella rhinoscleromatis (K.R.H.) is the bacterium responsible for rhinoscleroma, a granulomatous infection affecting the nose and paranasal sinuses. This bacterium causes a characteristic granulomatous inflammation, which leads to the disease's clinical manifestations.