In the given letter-cluster pairs, the first letter-cluster is related to the second letter-cluster following a certain logic. Study the given pairs carefully, and from the given options, select the pair that follows the same logic.
ABC:EFG
PQR:TUV

ABC:EFG
PQR:TUV

Logic: Each letter in the first cluster moves +4 places forward in the alphabet to form the second cluster.

In ABC → EFG
A + 4 → E
B + 4 → F
C + 4 → G
In PQR → TUV
P + 4 → T
Q + 4 → U
R + 4 → V
Checking Each Option:
Option (a): XYZ → BCD
X + 4 → B 
Y + 4 → C 
Z + 4 → D 
Matches the pattern.
Option (b): PKL → RSM
P + 2 → R 
K + 8 → S  
L + 1 → M 
Does not follow the pattern.
Option (c): MNO → PQR
M + 3 → P
N + 3 → Q 
O + 3 → R 
Does not follow the pattern.
Option (d): GHI → DEF
G - 3 → D 
H - 3 → E 
H - 3 → E
I - 3 → F 
Does not follow the pattern.
Thus, the correct option is (a) (XYZ → BCD) ​​​​