**Core Concept**
Acute pancreatitis is a complex inflammatory condition involving multiple organs, with potential complications including vascular damage. Pseudoaneurysm formation is a serious consequence, often resulting from arterial erosion due to pancreatic enzyme activity.

**Why the Correct Answer is Right**
The gastroduodenal artery is the most frequently involved artery in acute pancreatitis leading to pseudoaneurysm due to its proximity to the pancreas. This artery is located in close proximity to the pancreatic head and is more susceptible to damage from pancreatic enzymes. The gastroduodenal artery's location near the pancreatic head makes it vulnerable to inflammation and enzymatic degradation, increasing the risk of pseudoaneurysm formation.

**Why Each Wrong Option is Incorrect**
**Option A:** The splenic artery is involved in some cases of pancreatic pathology, but it is not the most frequently involved artery in acute pancreatitis leading to pseudoaneurysm.
**Option B:** The superior mesenteric artery is a major artery, but it is not typically involved in acute pancreatitis pseudoaneurysm formation.
**Option C:** The inferior mesenteric artery is not commonly associated with pancreatic pathology or pseudoaneurysm formation in acute pancreatitis.

**Clinical Pearl / High-Yield Fact**
The gastroduodenal artery's susceptibility to pseudoaneurysm formation highlights the importance of careful monitoring and management of pancreatic inflammation to prevent vascular complications.

**Correct Answer: C. Superior Mesenteric Artery is incorrect, the correct answer is D. Gastroduodenal Artery.**