Match List I with List II.
| List I | List II |
|---|---|
| A. P-wave | I. Beginning of systole |
| B. Q-wave | II. Repolarisation of ventricles |
| C. QRS complex | III. Depolarisation of atria |
| D. T-wave | IV. Depolarisation of ventricles |
Choose the correct answer from the options given below: