**Core Concept**
Myocardial infarction (MI) is characterized by the death of cardiac myocytes due to ischemia, leading to the loss of contractile function. The light microscopic changes in MI are primarily due to the coagulative necrosis of cardiac muscle cells.

**Why the Correct Answer is Right**
The coagulative necrosis in MI is caused by the denaturation of proteins and the loss of cellular structure, resulting in a firm, swollen cell with a preserved outline. This change is due to the activation of lysosomal enzymes and the release of calcium ions, leading to the disruption of cellular membranes and the eventual cell death. The presence of neutrophils and macrophages in the affected area is indicative of the inflammatory response.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it does not accurately describe the light microscopic changes in myocardial infarction. The changes in MI are not primarily due to fibrinoid necrosis, which is more characteristic of vasculitis.

**Option B:** This option is incorrect as it does not accurately describe the light microscopic changes in myocardial infarction. The changes in MI are not primarily due to caseous necrosis, which is more characteristic of tuberculosis.

**Option C:** This option is incorrect as it does not accurately describe the light microscopic changes in myocardial infarction. The changes in MI are not primarily due to liquefactive necrosis, which is more characteristic of brain tissue.

**Clinical Pearl / High-Yield Fact**
In myocardial infarction, the presence of coagulative necrosis is a hallmark of cell death, and the preservation of cellular outline is a key feature that distinguishes it from other types of necrosis.

**Correct Answer: C. Liquefactive necrosis is characteristic of brain tissue, not myocardial infarction.**