**Core Concept**
Caspases are a family of cysteine-aspartic acid proteases that play a crucial role in the execution phase of cell death, particularly in apoptosis (programmed cell death). They are essential for the cleavage of various substrates, leading to the characteristic morphological changes and cellular disintegration associated with apoptosis.

**Why the Correct Answer is Right**
Caspases are activated in a cascade, with initiator caspases (e.g., caspase-8 and caspase-9) cleaving and activating downstream executioner caspases (e.g., caspase-3 and caspase-7). These executioner caspases then cleave various substrates, including structural proteins, DNA repair enzymes, and other signaling molecules, ultimately leading to the characteristic features of apoptosis, such as cell shrinkage, chromatin condensation, and membrane blebbing.

**Why Each Wrong Option is Incorrect**
**Option A:** Caspases are not directly involved in the regulation of the cell cycle or DNA replication. While they can cleave and inactivate proteins involved in these processes, their primary role is in the execution of cell death.
**Option B:** Although caspases can cleave and activate certain kinases, they are not primarily involved in the regulation of cell signaling pathways. Their role is more focused on the execution of cell death rather than modulation of signaling.
**Option C:** Caspases are not directly involved in the regulation of inflammation or immune responses. While they can cleave and inactivate certain inflammatory mediators, their primary role is in the execution of cell death.

**Clinical Pearl / High-Yield Fact**
Caspases are a key point of intervention for cancer therapy, with many chemotherapeutic agents and targeted therapies aimed at inhibiting or modulating caspase activity to induce apoptosis in cancer cells. Understanding the role of caspases in apoptosis is crucial for the development of effective cancer treatments.

**Correct Answer: C. Apoptosis.**