**Core Concept**
Effacement of foot processes is a hallmark histological feature of certain glomerular diseases, indicating changes in the podocyte structure and function. This process is part of the podocyte injury cascade, leading to proteinuria and nephrotic syndrome. The effacement of foot processes is a critical diagnostic criterion for various glomerular diseases.

**Why the Correct Answer is Right**
The effacement of foot processes is a result of podocyte injury and detachment from the glomerular basement membrane. This is often due to the activation of the podocyte's mechanosensing pathways, leading to the disruption of the actin cytoskeleton and the foot process morphology. The effacement of foot processes is a key feature in diseases like minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), and membranous nephropathy (MN). The changes in foot process morphology can be visualized using electron microscopy.

**Why Each Wrong Option is Incorrect**
**Option A:** (not provided)
**Option B:** (not provided)
**Option C:** (not provided)
**Option D:** (not provided)

**Clinical Pearl / High-Yield Fact**
To remember the key features of glomerular diseases, one should recall the "P" acronym: "P"odocytes, "P"roteinuria, and "P"rotein loss. This will help in differentiating between various glomerular diseases and their characteristic features.

**Correct Answer:** C. Focal Segmental Glomerulosclerosis (FSGS)