**Core Concept**
Intracellular calcification is a process where calcium salts accumulate within cells, often leading to cell damage or death. This process is distinct from extracellular calcification, which occurs outside cells. The underlying mechanism involves abnormal cellular metabolism and an imbalance in calcium homeostasis.

**Why the Correct Answer is Right**
Intracellular calcification begins in the mitochondria, where calcium ions accumulate due to impaired mitochondrial function, increased oxidative stress, or altered calcium transport mechanisms. This accumulation triggers a series of events that ultimately lead to the precipitation of calcium salts within the mitochondria. The mitochondrial membrane is particularly susceptible to calcium overload, as it relies on calcium ions for normal functioning.

**Why Each Wrong Option is Incorrect**
**Option A:** Not applicable.
**Option B:** Incorrect, as calcification is not typically associated with the endoplasmic reticulum.
**Option C:** Incorrect, as lysosomes are involved in cellular digestion and recycling, not calcification.

**Clinical Pearl / High-Yield Fact**
Be aware of the clinical implications of intracellular calcification, particularly in the context of mitochondrial myopathies and cardiomyopathies. These conditions often present with muscle weakness, fatigue, and cardiac arrhythmias.

**Correct Answer:** C.