**Core Concept**
Lung fissures are thin walls of connective tissue that separate the lobes of the lungs. A bulging fissure is an abnormal protrusion of these fissures, which can be caused by various factors.

**Why the Correct Answer is Right**
Bulging fissures in the lung are typically seen in Pneumothorax, specifically in Tension Pneumothorax. In this condition, air enters the pleural space and is trapped, causing the lung to collapse. The increased pressure within the pleural space can lead to a bulging of the interlobar fissures. The mechanism behind this is the increased intrapleural pressure, which pushes the lung tissue against the rib cage, causing the fissures to bulge outward.

**Why Each Wrong Option is Incorrect**
**Option A:** Pneumonia - Pneumonia is an infection of the lung parenchyma and does not directly cause bulging fissures.
**Option B:** Pulmonary edema - Pulmonary edema is the accumulation of fluid in the lung tissue, which can cause the lung to become heavy and congested, but it does not typically cause bulging fissures.
**Option C:** Lung abscess - A lung abscess is a localized collection of pus in the lung tissue, which can cause destruction of the surrounding tissue, but it does not typically cause bulging fissures.

**Clinical Pearl / High-Yield Fact**
Bulging fissures in the lung are a clinical sign of a significant underlying condition, such as Tension Pneumothorax, and should be promptly recognized and managed to prevent further complications.

**Correct Answer:** C.