Step 1: Understand the semantic change types
- Narrowing: A word's meaning becomes more specific over time.
- Broadening: A word's meaning expands to include a wider range.
- Amelioration: A word develops a more positive meaning than before.
- Pejoration: A word develops a more negative meaning than before.
Step 2: Match each example with change type
- (i) silly: originally meant 'happy, prosperous', but now means 'foolish'. This is a shift to negative meaning → Pejoration (S-i).
- (ii) pretty: originally meant 'tricky, sly, cunning', but now means 'attractive'. This is a shift to positive meaning → Amelioration (R-ii).
- (iii) bead: originally meant 'prayer', but now refers specifically to a 'small decorative object'. This is a restricted meaning → Narrowing (P-iii).
- (iv) aunt: originally meant only 'father's sister', but now applies to all sisters of both parents. This is an expanded meaning → Broadening (Q-iv).
Step 3: Final Sequence
- P (narrowing) → iii (bead)
- Q (broadening) → iv (aunt)
- R (amelioration) → ii (pretty)
- S (pejoration) → i (silly)
Thus, the correct matching sequence is: P-iii; Q-iv; R-ii; S-i.
\[
\boxed{\text{Correct Answer: (A)}}
\]