This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Parathyroid & Adrenal Glands), Subject name: Surgery
When should a nonfunctioning adrenal tumor be operated - 
Select and explain. 
A. 1 cm, B. 2 cm, C. 3 cm, D. 4 cm
D: 4 cm
Answer: D: 4 cm 
Explanation: Ans. is 'd' i.e., 4 cm. Adrenal incidentalomaso Patients with functional tumors or obviously malignant lesions should undergo adrenolectomyo For non-functional tumors -Size < 3 cm -- 6/12 monthly CT/MRI follow up.Size 3 -5 cm -- Adrenalectomy in fit patient.Size >5 cm -- Adrenalectomy.