## **Core Concept**
The question tests the knowledge of peptides that affect capillary permeability and cause edema. This involves understanding the role of various peptides in inflammation and vascular permeability. The correct answer is related to a peptide known for its effect on increasing capillary 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 process. Bradykinin works by binding to its receptors on the endothelial cells lining blood vessels, leading to the contraction of these cells and the formation of gaps between them. This results in increased vascular permeability, allowing fluid and proteins to leak into the interstitial space, which manifests clinically as edema.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and does not provide a peptide for consideration.
- **Option B:** This option is also blank and does not offer a relevant peptide.
- **Option D:** This option is blank as well, providing no potential peptide for evaluation.

## **Clinical Pearl / High-Yield Fact**
A key clinical correlation to remember is that drugs which inhibit the conversion of angiotensin I to angiotensin II, known as ACE inhibitors, can lead to increased levels of bradykinin as a side effect. This is because ACE is also involved in the breakdown of bradykinin. Increased bradykinin levels can cause cough and angioedema in some patients taking ACE inhibitors.

## **Correct Answer:** .