**Core Concept**
Aspergillosis, a type of fungal infection, is a common cause of invasive sinusitis in immunocompromised individuals, particularly those with uncontrolled diabetes mellitus. The pathogenesis involves the inhalation of Aspergillus spores, which colonize the nasal mucosa and cause tissue destruction.

**Why the Correct Answer is Right**
Aspergillosis is caused by the Aspergillus species, specifically Aspergillus fumigatus, which is the most common causative agent. The organism invades the nasal mucosa and causes necrosis due to the production of proteolytic enzymes, such as elastase and collagenase. The black necrotic mass is a characteristic feature of aspergillosis, resulting from the accumulation of melanin produced by the fungus.

**Why Each Wrong Option is Incorrect**
**Option A:** Histoplasma capsulatum is a cause of histoplasmosis, a different type of fungal infection that primarily affects the lungs.
**Option B:** Candida albicans is a common cause of mucocutaneous candidiasis, particularly in immunocompromised individuals, but it is not typically associated with black necrotic masses in the nasal cavity.
**Option C:** Mucormycosis is another type of fungal infection that can cause invasive sinusitis, but it is more commonly associated with rhinocerebral involvement and typically presents with more severe symptoms.

**Clinical Pearl / High-Yield Fact**
Uncontrolled diabetes mellitus is a significant risk factor for invasive fungal infections, particularly aspergillosis and mucormycosis. Early recognition and treatment of these infections are critical to prevent severe complications and mortality.

**Correct Answer:** A. Aspergillus species.