Which one of the following is a possibility for most of us in regard to breathing, by making a conscious effort?

Options

(a) One can breathe out air totally without oxygen
(b) One can breathe out air through eustachian tubes by closing both the nose and the mouth
(c) One can consiously breathe in and breathe out by moving the diaphragm alone, without moving the ribs at all
(d) The lungs can be made fully empty by forcefully breathing out all air from them

Correct Answer:

One can breathe out air through eustachian tubes by closing both the nose and the mouth

Explanation:

Eustachian tube connect middle ear cavity(Tympanic cavity) with nasopharynx, approximately it is 35 mm long in adults, which helps in breathing out by closing both the nose and mouth.