Four letter-clusters have been given, out of which three are alike in some manner and one is different. Select the letter-cluster that is different.

To determine which letter-cluster is different, we analyze the alphabetical positions of the letters in each cluster and look for a consistent pattern of differences between consecutive letters.

Let us first write down the numerical positions of the letters in the English alphabet (A = 1, B = 2, ..., Z = 26):
A: 1, B: 2, C: 3, D: 4, E: 5, F: 6, G: 7, H: 8, I: 9, J: 10, K: 11, L: 12, M: 13, N: 14, O: 15, P: 16, Q: 17, R: 18, S: 19, T: 20, U: 21, V: 22, W: 23, X: 24, Y: 25, Z: 26.

Now, we calculate the differences between consecutive letters for each cluster:

1. TVYCH:
T (20) → V (22): +2
V (22) → Y (25): +3
Y (25) → C (3, or 29): +4
C (3) → H (8): +5
The pattern of differences is: +2, +3, +4, +5.

2. NPSWB:
N (14) → P (16): +2
P (16) → S (19): +3
S (19) → W (23): +4
W (23) → B (2, or 28): +5
The pattern of differences is: +2, +3, +4, +5.

3. UWZBI:
U (21) → W (23): +2
W (23) → Z (26): +3
Z (26) → B (2, or 28): +2
B (2) → I (9): +7
The pattern of differences is: +2, +3, +2, +7. This does not follow the +2, +3, +4, +5 pattern.

4. ACFJO:
A (1) → C (3): +2
C (3) → F (6): +3
F (6) → J (10): +4
J (10) → O (15): +5
The pattern of differences is: +2, +3, +4, +5.

Comparing the results, the clusters TVYCH, NPSWB, and ACFJO all follow the same pattern of differences (+2, +3, +4, +5), whereas the cluster UWZBI does not.

Therefore, the different letter-cluster is UWZBI.