This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: ENT
Periodicity is a characteristic feature in which sinus infection: 
Select and explain. 
A. Maxillary sinus infection, B. Frontal sinus infection, C. Sphenoid sinus infection, D. Ethmoid sinus infection
B: Frontal sinus infection
Answer: B: Frontal sinus infection 
Explanation: Areas of High attenuation surrounded by a thin zone of low attenuation CT scan reveals pansinusitis and polyposis Pain of frontal sinusitis shows characteristic periodicity, i.e. comes upon waking, gradually increases and reaches its peak by midday and then stas subsiding. It is also called "office headache" as it is present only during office hours.