Which of the following is a very unique feature of the mammalian body?

In which of the following is the diaphragm found?

The structure which prevents the entry of food into the respiratory tract is

The total surface area of the human lungs,specifically the respiratory surface area provided by the alveoli,is approximately: (in $; m^{2}$)

Which of the following statements is true regarding the human respiratory system?

The figure shows a diagrammatic view of the human respiratory system with labels $A, B, C$,and $D$. Select the option which gives the correct identification and main function and/or characteristic.