Explanation:

Let’s break it down:

- COLD ? GTRK

- Look at each letter:

- C (3rd letter of alphabet) + 4 = G (7th letter)

- O (15th) + 4 = S (19th) – but they wrote T (20th). That’s odd. Let's check all:

- O ? T (+5)

- L (12th) + 4 = P (16th), but cluster has R (18th)

- D (4th) + 4 = H (8th), got K (11th)

- Okay, so the difference is:

- C to G = +4

- O to T = +5

- L to R = +6

- D to K = +7

- So, pattern is:

First letter +4, second letter +5, third letter +6, fourth letter +7.

- Now do MICE:

- M (13th) +4 = Q (17th)

- I (9th) +5 = N (14th)

- C (3rd) +6 = I (9th)

- E (5th) +7 = L (12th)

- So, MICE becomes QNIL.

Let’s map this to the options:

- Option 1: RMGL

- Option 2: QNGL

- Option 3: QNIL

- Option 4: QMGL

Here’s what this means: Option 3: QNIL is the only one that fits the pattern exactly.

The answer is Option 3: QNIL.