Explanation:

- The relationship between PAN and SCP can be analyzed by examining the change in each corresponding letter.

- P to S is a shift of +3 in the alphabet (P-Q-R-S).

- A to C is a shift of +2 (A-B-C).

- N to P is a shift of +2 (N-O-P).

- Apply the same logic to HOP:

- H to K is a shift of +3 (H-I-J-K).

- O to Q is a shift of +2 (O-P-Q).

- P to S is a shift of +3 (P-Q-R-S).

- Given this pattern, the correct letter-cluster is KQS.

- Options:

- Option 4: KQS is the correct answer.

- Option 1: KQR is not correct as it doesn't follow the pattern.

- Option 2: KRQ is not correct due to incorrect sequence.

- Option 3: KSQ is not correct owing to incorrect shifts.

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