You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is True about sphenoid sinus - and explain in detail?
All paranasal sinuses are lined by respiratory epithelium (i.e. ciliated pseudo stratified columnar epithilium) i.e. option a is incorrect.

Sphenoid sinus: Important points

It is not present at birth
It occupies the body of sphenoid
Ostrum of sphenoid sinus is situated in the upper part of anterior wall and drains into spheno ethmoidal recess.
On x ray: Sphenoid sinus is visible by 4 years of age.