Physiology Vital capacity is: A Tidal volume + Expiratory Reserve Volume B Tidal volume + Inspiratory Reserve Volume C I.R.V. + E. R.V. D T.V. + I.R.V. + E.R.V. 💡 Explanation Vital capacity is: ✓ Correct Answer: D. T.V. + I.R.V. + E.R.V.