**Core Concept**
Coagulative necrosis is a type of cell death characterized by the preservation of cell outlines and a firm, dry texture, often due to ischemia or infarction. This process involves the denaturation of proteins, leading to cell membrane disruption and eventual cell lysis.

**Why the Correct Answer is Right**
In gangrene, coagulative necrosis occurs due to prolonged ischemia, which leads to a lack of oxygen and nutrients, causing cellular damage and death. The denaturation of proteins and cellular swelling result in a firm, dry texture, characteristic of coagulative necrosis. The combination of reduced blood flow and bacterial infection in gangrene further exacerbates the ischemic damage, leading to extensive tissue necrosis.

**Why Each Wrong Option is Incorrect**
**Option A:** Tuberculosis (TB) typically causes caseous necrosis, a type of necrosis characterized by a soft, cheesy texture, often due to the presence of Mycobacterium tuberculosis.
**Option B:** Sarcoidosis is a granulomatous disease that typically causes non-caseating granulomas, which are not associated with coagulative necrosis.
**Option D:** Cryptococcal infection can cause necrotizing inflammation, but it is not typically characterized by coagulative necrosis.

**Clinical Pearl / High-Yield Fact**
Coagulative necrosis is often seen in tissues with a high protein content, such as the liver, heart, and kidneys. This type of necrosis is typically reversible in its early stages, but prolonged ischemia can lead to permanent cell death and tissue damage.

✓ Correct Answer: C. Gangrene.