**Core Concept**
Adrenal incidentaloma refers to a benign adrenal tumor discovered incidentally during imaging for unrelated conditions. The decision for surgical intervention depends on tumor size, function, and presence of metastatic disease, as these factors influence risk of malignancy, hormone secretion, and clinical impact.

**Why the Correct Answer is Right**
- **Size >5 cm**: Tumors larger than 5 cm have a significantly increased risk of malignancy (up to 20–30%), and surgery is indicated to rule out cancer and prevent complications.
- **Bilateral adrenal metastasis**: This indicates widespread disease, often from a systemic malignancy, and surgical removal is not curative but may be considered for symptom control or diagnostic clarification.
- **Functional tumor**: Tumors producing hormones (e.g., Cushing’s, pheochromocytoma, hyperaldosteronism) cause symptoms and require surgical removal to correct hormonal imbalance.
Thus, all listed scenarios warrant surgical evaluation or intervention.

**Why Each Wrong Option is Incorrect**
Option A: While size >5 cm is a key indicator, it is not the only factor—some smaller tumors may be malignant or functional. This option alone is insufficient.
Option B: Bilateral adrenal metastasis is not a direct indication for surgery; it reflects advanced disease, and surgical management is typically palliative or supportive.
Option C: Functional tumors require surgery due to hormone excess, but the absence of function does not rule out need for surgery in large or suspicious tumors.

**Clinical Pearl / High-Yield Fact**
Always assess function and size of adrenal incidentalomas—**functional tumors and those >5 cm** are surgical candidates, while **bilateral metastasis** implies systemic cancer and may require surgical intervention for symptom relief or diagnostic purposes.

✓ Correct Answer: D. All of the above