**Core Concept**
Rapidly Progressive Glomerulonephritis (RPGN) is a syndrome characterized by a rapid decline in renal function, often accompanied by severe oliguria and hematuria. It is typically associated with severe glomerular injury and inflammation, which can lead to acute kidney injury and potentially end-stage renal disease.

**Why the Correct Answer is Right**
RPGN is characterized by the presence of crescents, which are collections of proliferating epithelial cells and monocytes in Bowman's space. This feature is a hallmark of RPGN and is associated with severe glomerular injury. Other features of RPGN include severe oliguria, hematuria, and a rapid decline in renal function.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because RPGN can indeed present with hypertension.
**Option B:** This option is incorrect because RPGN can be associated with systemic symptoms such as fever and weight loss.
**Option C:** This option is incorrect because RPGN can be associated with the presence of hematuria.

**Clinical Pearl / High-Yield Fact**
One key clinical feature of RPGN is the presence of crescents, which are collections of proliferating epithelial cells and monocytes in Bowman's space. This feature can be identified on kidney biopsy and is a hallmark of severe glomerular injury.

**Correct Answer: C. Hypotension**