In which animal does the tongue help in thermoregulation?

The given figure shows the human respiratory system with structures labeled $A, B, C,$ and $D$. Which of the following options correctly identifies the structure and its main function or characteristic?

Given below are two statements regarding the respiratory system of man.
$Statement-I$: Epiglottis prevents the entry of food into the trachea.
$Statement-II$: The internal lining of the trachea is made up of ciliated epithelium only.
In the light of the above statements, choose the most appropriate answer from the options given below:

The largest cartilage of the larynx,which is in the form of a broad ring and is incomplete posteriorly,is:

Which is the narrowest and most delicate tube in the lungs?

Which features distinguish bronchioles from bronchi?