Step 1: Datum is defined as a line, plane, or volume that organizes forms and spaces through continuity and regularity. This corresponds to P–4.
Step 2: Symmetry describes the balanced distribution of equivalent forms and spaces around a central line or point. This matches Q–2.
Step 3: Hierarchy indicates the importance of a form or space based on its size, shape, or relative position within an organization. This is described by R–5.
Step 4: Rhythm in design involves the application of recurring patterns to structure a series of similar forms or spaces. This is designated as S–1.
Conclusion: The correct pairings are P–4, Q–2, R–5, and S–1, which aligns with option (C).