This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Oral Cavity, Subject name: ENT
A 50-year-old male presents with a growth in the buccal mucosa. Growth measures 3 cm in its greatest dimension. He also has multiple nodes on the ipsilateral side in the submandibular region but none of the nodes is more than 3 cm. Your line of treatment is: 
Select and explain. 
A. Radiotherapy to the primary and lymph nodes of the neck, B. Radiotherapy to the primary with supraomohyoid neck dissection, C. Surgical excision of the primary growth and supraomohyoid neck dissection, D. Surgical excision of growth, supraomohyoid neck dissection and post-operative radiotherapy
D: Surgical excision of growth, supraomohyoid neck dissection and post-operative radiotherapy
Answer: D: Surgical excision of growth, supraomohyoid neck dissection and post-operative radiotherapy 
Explanation: Growth which measures more than 3 cm is classified as T2 Multiple ipsilateral nodes none more than 3 cm is N2 . The growth (T2 N2 ) thus will be stage III.Treatment of stage III is surgical excision of growth with supraomohyoid (levels I, II and III nodes) neck dissection followed by post-operative radiotherapy.