Correct matches based on migration type definitions are as follows:
Involuntary migration (P): Defined as forced displacement due to conflict, disaster, or persecution. This corresponds to (3) Forced displacement from their origin to destination areas.
Step migration (Q): Characterized by a migrant's progression through a series of stages or stops en route to a final destination. This matches (1) When a migrant follows a path or series of stages towards a final destination.
Circular migration (R): Involves a migrant worker's repeated travel between their home and destination areas, typically for employment. This aligns with (2) Repetitive movement of a migrant worker between home and destination areas.
Chain migration (S): Occurs when individuals from a specific region follow others from the same region to a particular destination. This is described by (4) Immigrants from a particular area follow others from that area to a particular destination.
Conclusion: The definitive pairings are (P–3, Q–1, R–2, S–4), which corresponds to option (B).