Step 1: Understanding the Question:
We need to find the next 4-letter cluster in the alphabetical sequence.
Step 2: Detailed Explanation:
Breaking the clusters into two parts: Each term has a pair of letters at the start (WX, UV, ST, QR) and a pair at the end (CD, EF, GH, IJ).
Analyzing the first pair (WX, UV, ST, QR):
- WX (23, 24) $\rightarrow$ UV (21, 22): Shift of -2
- UV (21, 22) $\rightarrow$ ST (19, 20): Shift of -2
- ST (19, 20) $\rightarrow$ QR (17, 18): Shift of -2
- Next pair: (17-2, 18-2) = (15, 16) $\rightarrow$ OP
Analyzing the second pair (CD, EF, GH, IJ):
- CD (3, 4) $\rightarrow$ EF (5, 6): Shift of +2
- EF (5, 6) $\rightarrow$ GH (7, 8): Shift of +2
- GH (7, 8) $\rightarrow$ IJ (9, 10): Shift of +2
- Next pair: (9+2, 10+2) = (11, 12) $\rightarrow$ KL
Combining the results: OP + KL = OPKL.
Step 3: Final Answer:
The next term in the series is OPKL. Option (A) is correct.