Diaphragm is found in

Which portion of the human respiratory system is called the sound box?

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 division of mammalian lungs into a very large number of tiny alveoli around alveolar ducts opening into bronchioles is:

Which of the following organisms possesses the most developed respiratory system?

Select the $INCORRECT$ statement.