**Core Concept**
Adrenal incidentalomas are non-functioning adrenal tumors discovered incidentally on imaging studies. The decision to proceed with surgery depends on several factors, including the tumor's size, imaging characteristics, hormonal activity, and patient symptoms.

**Why the Correct Answer is Right**
Surgery is indicated for adrenal incidentalomas that are large (>4 cm), have a high risk of malignancy, or are causing symptoms such as hypertension or hormonal imbalances. The primary concern is the potential for adrenal cortical carcinoma, which is a rare but aggressive malignancy.

* **Option A:** This option is incorrect because a small adrenal incidentaloma (4 cm, have a high risk of malignancy, or are causing symptoms or signs of hormonal excess.

**Correct Answer: C.