Paranasal sinuses present at birth are: (A) Frontal and maxillary, (B) Ethmoid and maxillary, (C) Frontal and ethmoid, (D) Sphenoid and ethmoid
Answer is B. Paranasal sinuses develop as outpouchings from the mucous membrane of a lateral wall of the nose. 
The growth of sinuses continues during childhood and into early adult life.
Radiologically maxillary sinuses can be identified at 4-5 months, ethmoids at 1 year,  sphenoid at 4 years and frontals at 6 years.