The common passage for food and air is

The $Larynx$ is present between:

During swallowing,the glottis can be covered by a thin elastic cartilaginous flap called $A$ to prevent the entry of food into the larynx. The trachea is a straight tube extending up to the $B$ cavity,which divides at the level of the $5^{th}$ thoracic vertebra into right and left primary $C$. Choose the correct option for $A, B$,and $C$ from the given four options to complete the above statement with reference to the $NCERT$ textbook.

The respiratory system is derived from which germ layer?

The thoracic chamber is formed of ........

The nasal cavity contains a large number of which of the following cells?