## Core Concept
The question targets the understanding of peptides that affect capillary permeability and induce edema. This involves knowledge of various peptides and their physiological effects, particularly those involved in inflammatory responses and vascular permeability.

## Why the Correct Answer is Right
Bradykinin is a peptide that causes increased capillary permeability and edema. It is a key mediator in the inflammatory response and is known to cause blood vessels to dilate (vasodilation) and increase vascular permeability. This leads to increased blood flow to the affected area and the leakage of fluid from the capillaries into the interstitial space, resulting in edema. Bradykinin exerts its effects by binding to specific receptors on endothelial cells, leading to the production of nitric oxide and prostacyclin, which in turn cause vasodilation and increased permeability.

## Why Each Wrong Option is Incorrect
**Option A:** While certain prostaglandins can influence vascular tone and permeability, they are not typically described as peptides.

**Option B:** Histamine is a biogenic amine, not a peptide, and it does cause increased capillary permeability and edema. However, it is not a peptide.

**Option D:** Angiotensin II is a peptide but primarily causes vasoconstriction and is involved in blood pressure regulation through the renin-angiotensin-aldosterone system. It does not primarily cause increased capillary permeability and edema like bradykinin.

## Clinical Pearl / High-Yield Fact
A key clinical pearl is that bradykinin is involved in the pathophysiology of angioedema, a condition characterized by rapid swelling of the dermis, subcutaneous tissue, mucosa, and submucosal tissues. It can be hereditary (due to C1 inhibitor deficiency) or acquired. Understanding the role of bradykinin in this condition is crucial for diagnosis and treatment.

## Correct Answer: C. Bradykinin