**Core Concept**
Inflammatory bowel disease (IBD), encompassing conditions like Crohn's disease and ulcerative colitis, is characterized by chronic inflammation of the gastrointestinal tract. Extraintestinal manifestations occur when IBD affects organs outside the gastrointestinal tract. The most common extraintestinal manifestations of IBD are related to the immune system's aberrant response and the subsequent inflammatory cascade.

**Why the Correct Answer is Right**
The most common extraintestinal manifestation of IBD is axial arthritis, particularly sacroiliitis. This occurs due to the shared genetic predisposition between IBD and spondyloarthritis. The immune system's dysregulation leads to the activation of pro-inflammatory cytokines, which in turn cause inflammation in the joints and spine. The HLA-B27 antigen is often associated with IBD and plays a crucial role in the development of axial arthritis.

**Why Each Wrong Option is Incorrect**
**Option A:** Peripheral arthritis, while a possible extraintestinal manifestation of IBD, is less common than axial arthritis.
**Option B:** Dermatological manifestations, such as erythema nodosum and pyoderma gangrenosum, are less frequent than axial arthritis in IBD patients.
**Option C:** Hepatic manifestations, including primary sclerosing cholangitis, are also less common than axial arthritis in IBD patients.
**Option D:** Ocular manifestations, such as uveitis, are rare in IBD patients compared to axial arthritis.

**Clinical Pearl / High-Yield Fact**
Remember the "BIM" acronym to associate with extraintestinal manifestations of IBD: Bones (axial arthritis), Integument (dermatological manifestations), and Muscles (myositis).

**Correct Answer:** C.