Which of the following letter-number clusters will replace the question mark (?) in the given series to make it logically complete?

SWC67, XBH56, CGM45, HLR34, ?

The correct option is MQW23.

To find the letter-number cluster that replaces the question mark (?), let us analyze the patterns of the letters and the numbers in the given series step-by-step:
The given series is: SWC67, XBH56, CGM45, HLR34, ?

Let's first analyze the number part at the end of each cluster:
67, 56, 45, 34, ...
We can see that the numbers are decreasing by 11 in each step:
67 - 11 = 56
56 - 11 = 45
45 - 11 = 34
Following this pattern, the next number will be:
34 - 11 = 23

Now, let's analyze the letter parts of the clusters by looking at the alphabetical position of each letter (where A = 1, B = 2, ..., Z = 26):

First letter pattern: S, X, C, H, ...
S (19) $\to$ (+5) $\to$ X (24)
X (24) $\to$ (+5) $\to$ C (3, because 24 + 5 = 29, and 29 - 26 = 3)
C (3) $\to$ (+5) $\to$ H (8)
Following this +5 pattern, the next first letter should be:
H (8) + 5 = 13, which corresponds to the letter M.

Second letter pattern: W, B, G, L, ...
W (23) $\to$ (+5) $\to$ B (2, because 23 + 5 = 28, and 28 - 26 = 2)
B (2) $\to$ (+5) $\to$ G (7)
G (7) $\to$ (+5) $\to$ L (12)
Following this +5 pattern, the next second letter should be:
L (12) + 5 = 17, which corresponds to the letter Q.

Third letter pattern: C, H, M, R, ...
C (3) $\to$ (+5) $\to$ H (8)
H (8) $\to$ (+5) $\to$ M (13)
M (13) $\to$ (+5) $\to$ R (18)
Following this +5 pattern, the next third letter should be:
R (18) + 5 = 23, which corresponds to the letter W.

Combining the letters (M, Q, W) and the number (23), the next cluster in the series is MQW23.