The following stages are part of yoghurt production: 1 liquid cooled rapidly; 2 liquid kept at $40-45\,^\circ\text{C}$ for 3 hours; 3 culture of bacteria added to liquid; 4 liquid pasteurised. In what sequence do these stages take place?
- A1 → 2 → 3 → 4
- B2 → 1 → 4 → 3
- C3 → 4 → 1 → 2
- D4 → 3 → 2 → 1