**Core Concept**
The question is testing the understanding of the timeline of myocardial infarction (MI) pathology, specifically the sequence of reversible and irreversible myocardial injury. The underlying concept is the pathophysiology of ischemia-reperfusion injury in the heart.

**Why the Correct Answer is Right**
Irreversible injury to the myocardium in MI occurs earliest due to coagulative necrosis caused by prolonged ischemia. This process is initiated when the duration of ischemia exceeds the threshold for irreversible damage, typically around 20-30 minutes. The lack of oxygen and nutrients leads to cellular swelling, mitochondrial dysfunction, and ultimately, cell death. The myocardial cells undergo coagulative necrosis, leading to a loss of cell membrane integrity and the release of intracellular contents.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the initial phase of MI is characterized by reversible injury, not irreversible damage. Reversible injury is caused by ischemia for shorter durations, which can be reversed with timely reperfusion.
**Option B:** This option is incorrect because the process of apoptosis, or programmed cell death, is a secondary mechanism of cell death that occurs later in the course of MI, after the initial phase of coagulative necrosis.
**Option C:** This option is incorrect because the process of autolysis, or self-digestion of cells, is a late event in the course of MI, occurring after the release of lysosomal enzymes from damaged cells.

**Clinical Pearl / High-Yield Fact**
The "golden hour" in MI refers to the critical first hour after symptom onset, during which timely reperfusion therapy can reverse reversible injury and limit the extent of irreversible damage.

**Correct Answer: C. 20-30 minutes**