**Core Concept**
The management of pancreatic cysts involves a multidisciplinary approach, considering the size, location, symptoms, and potential for malignancy. The treatment of choice depends on the cyst's characteristics and the patient's clinical presentation.

**Why the Correct Answer is Right**
The treatment of choice for a symptomatic pancreatic cyst of 7 cm in size is surgical resection, specifically a distal pancreatectomy or a total pancreatectomy, depending on the cyst's location and the patient's overall health. This approach is recommended because larger cysts are at higher risk of harboring malignancy, and surgical resection offers the best chance for cure. The decision to operate is also influenced by the patient's symptoms, such as abdominal pain or jaundice, which may worsen over time.

**Why Each Wrong Option is Incorrect**
**Option A:** Cyst aspiration and drainage may be an option for smaller, asymptomatic cysts, but it is not the treatment of choice for a symptomatic cyst of 7 cm in size, as it may not prevent recurrence and does not address the risk of malignancy.
**Option B:** Observation alone is not recommended for symptomatic pancreatic cysts, as it may lead to delayed diagnosis and treatment of potential malignancy.
**Option C:** Endoscopic resection may be an option for smaller, non-invasive cysts, but it is not suitable for larger symptomatic cysts, which require a more definitive surgical approach.

**Clinical Pearl / High-Yield Fact**
Surgical resection of pancreatic cysts is recommended for symptomatic cysts larger than 3 cm, as they are at higher risk of harboring malignancy.

**Correct Answer: D. Surgical resection**