Match the following columns and select the correct option:
| Column I | Column II |
| (a) Pneumotaxic centre | (i) Alveoli |
| (b) O2 Dissociation curve | (ii) Pons region of brain |
| (c) Carbonic Anhydrase | (iii) Haemoglobin |
| (d) Primary site of exchange of gases | (iv) RBC |
a-ii, b-iii, c-iv, d-i
a-iii, b-ii, c-iv, d-i
a-iv, b-i, c-iii, d-ii
a-i, b-iii, c-ii, d-iv