Which of the following is necessary to supply the body with O₂ and dispose of CO₂?
a) Pulmonary ventilation
b) Adjustment of blood pH
c) External respiration
d) Transport of respiratory gases
a) 1 and 3 only are correct answers
b) 2, 4 only are correct answers
c) 1 - 4 are all correct answers
d) 1, 3, 4 only are correct answers
