**Core Concept**
Bariatric surgery is a surgical procedure aimed at weight loss and reduction of comorbidities in obese patients. The effectiveness of bariatric surgery depends on the type of procedure, patient selection, and post-operative care. The goal is to achieve significant weight loss and improvement in metabolic and cardiovascular risk factors.

**Why the Correct Answer is Right**
Among various bariatric procedures, Roux-en-Y gastric bypass (RYGB) has been shown to have the maximum benefits and comorbidity reduction. RYGB involves creating a small stomach pouch and rerouting the small intestine to promote weight loss and improve insulin sensitivity. This procedure leads to significant reduction in body mass index (BMI), type 2 diabetes, hypertension, and dyslipidemia.

**Why Each Wrong Option is Incorrect**
**Option A:** Sleeve gastrectomy is another effective bariatric procedure, but it has a lower impact on comorbidity reduction compared to RYGB.
**Option B:** Adjustable gastric banding is a less invasive procedure, but it has lower long-term weight loss and comorbidity reduction rates compared to RYGB.
**Option C:** Biliopancreatic diversion with duodenal switch is a more complex procedure with higher risks, but it has shown promising results in comorbidity reduction.

**Clinical Pearl / High-Yield Fact**
RYGB is associated with significant improvement in type 2 diabetes resolution rates, with up to 80% of patients achieving remission within 2 years post-surgery.

**Correct Answer: C. Biliopancreatic diversion with duodenal switch is a more complex procedure with higher risks, but it has shown promising results in comorbidity reduction.**