Explanation:

The given pair is TANK : NATK.

- Relationship Explanation: In TANK : NATK, the first two letters are swapped with each other and the last two letters remain in the same order.

Now, let's analyze the options:

1. LEFT : ELFT

- The first two letters (L and E) are swapped.

- The last two letters (F and T) remain unchanged.

2. PING : NIPG

- The first two letters (P and I) are swapped.

- The last two letters (N and G) remain unchanged.

3. SAMP : AMSP

- The first two letters (S and A) are swapped.

- The last two letters (M and P) remain unchanged.

4. KORB : ROBK

- The first two letters (K and O) are swapped.

- The last two letters (R and B) do not remain unchanged; this is not the correct pattern.

?? Correct Answer: PING : NIPG follows the same pattern.