Select the letter-cluster from the given options that can replace the question mark (?) in the following series.
TSF, RPJ, PMN, NJR, ?

The correct option is LGV.

To find the letter-cluster that replaces the question mark (?) in the series, let us analyze the pattern by examining the letters at each position in the clusters:
TSF, RPJ, PMN, NJR, ?

1. First letter of each cluster:
The first letters are: T, R, P, N, ...
Let's look at their positions in the alphabetical order (A = 1, B = 2, ..., Z = 26):
T = 20
R = 18 (20 - 2)
P = 16 (18 - 2)
N = 14 (16 - 2)
Following this pattern, the next first letter should be:
14 - 2 = 12, which corresponds to the letter L.

2. Second letter of each cluster:
The second letters are: S, P, M, J, ...
Let's look at their positions in the alphabetical order:
S = 19
P = 16 (19 - 3)
M = 13 (16 - 3)
J = 10 (13 - 3)
Following this pattern, the next second letter should be:
10 - 3 = 7, which corresponds to the letter G.

3. Third letter of each cluster:
The third letters are: F, J, N, R, ...
Let's look at their positions in the alphabetical order:
F = 6
J = 10 (6 + 4)
N = 14 (10 + 4)
R = 18 (14 + 4)
Following this pattern, the next third letter should be:
18 + 4 = 22, which corresponds to the letter V.

Combining these letters, the next cluster in the series is LGV.