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: A frontal headache is usually severe and localized over affected sinus. 
It shows characteristic periodicity, ie., comes upon waking, gradually increases and reaches its peak by about midday and then starts subsiding.
It is also called "an office headache" because of its presence during the office hours.