This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Diagnostic and operative ENT, Subject name: ENT
Alpha Lynch Howah surgery is for 
Select and explain. 
A. Nasal septal perforation, B. Chronic frontal sinusitis, C. Acoustic neuroma, D. Otosclerosis
B: Chronic frontal sinusitis
Answer: B: Chronic frontal sinusitis 
Explanation: External frontoethmoidectomy (Howah's or Lynch operation) - The frontal sinus is entered through its floor by a curvilinear incision round the inner margin of the orbit. Diseased mucosa is removed, ethmoid cells exenterated and a new frontonasal duct created. Ref- Dhingra, 6th edition , page 196.