To answer this item, we assume that the air is an ideal gas such that it follows the equation,
PV = nRT
The pressure of the lungs of the person should be in equilibrium to that of the surrounding, making it 1 atm. Substituting the known values to the equation,
n = (1 atm)(2L)/(0.0821 L.atm/mol.K)(37 + 273.15)
n = 0.0785 moles
Answer: 0.0785 moles