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

Options

A. One can consciously breathe in and breathe our by moving the diaphrangm alone, without moving the ribs at all
B. The lungs can be made fully empty by forccfully emply by forcefully breathing out all air from them
C. One can breathe out air totally without oxygen
D. One can breathe out air through Eustachian tubes by closing both the more and the mouth

Answer

A