Which of the following letter-clusters should replace # and % so that the pattern and relationship followed between the letter-cluster pair on the left side of :: is the same as that on the right side of :: ?

# : IGC :: TRN : %

The correct option is # = LJF; % = QOK.

To find the correct letter-clusters for # and %, let us analyze the pattern followed between the letter-cluster pairs on both sides of the analogy: # : IGC :: TRN : %.

Let us test the values given in the correct option, where # = LJF and % = QOK:

Left side pair (# : IGC → LJF : IGC):

Comparing the corresponding positions of letters from LJF to IGC using alphabetical positional values:

1. First letter: L (12) → I (9) : -3
2. Second letter: J (10) → G (7) : -3
3. Third letter: F (6) → C (3) : -3

Each letter in the first cluster is shifted backwards by 3 positions to get the second cluster.

Right side pair (TRN : % → TRN : QOK):

Applying the exact same rule (subtracting 3 from the alphabetical positions of TRN):

1. First letter: T (20) - 3 = 17 → Q
2. Second letter: R (18) - 3 = 15 → O
3. Third letter: N (14) - 3 = 11 → K

Thus, % is replaced by QOK.

Since both pairs follow the same positional pattern of subtracting 3 from each letter's alphabetical rank (-3, -3, -3), the replacement pair # = LJF; % = QOK is correct.