Match each item in Column I with one item in Column II and choose your answer from the codes given below:
| Column I | Column II | ||
| I. | Influx of sodium | 1. | Original establishment of RMP | 
| II. | Efflux of potassium | 2. | Repolarization | 
| III. | Na+/K+ pump | 3. | Depolarization | 
| IV. | Ca++ | 4. | Plateau in cardiac muscles | 
Codes :
| I | II | III | IV | |
| 1. | 3 | 2 | 4 | 1 | 
| 2. | 2 | 1 | 4 | 3 | 
| 3. | 2 | 1 | 3 | 4 | 
| 4. | 3 | 2 | 1 | 4 |