When We Breathe We Inhale Oxygen, O₂, and Exhale Carbon

When we breathe we inhale oxygen, O₂, and exhale carbon dioxide, CO₂, plus water vapor, H₂O. Which likely has more mass, the air that we inhale or the same volume of air we exhale? Does breathing cause you to lose or gain weight?

A) The air we inhale has more mass; Breathing causes you to lose weight.
B) The air we exhale has more mass; Breathing causes you to lose weight.
C) The air we inhale has more mass; Breathing causes you to gain weight.
D) The air we exhale has more mass; Breathing causes you to gain weight.