Which of the following is true about paranasal sinuses?
A) Paranasal sinuses open into the oral cavity.
B) Paranasal sinuses enhance the resonance of the voice and lighten the skull.
C) Paranasal sinuses contain passages acting as one-way valves.
D) Paranasal sinuses are found in maxillary, ethmoid, and lacrimal bones.
Answer: B