Explanation:

Let’s break down the code:

- Check for a letter pattern:

- ‘WORD’ ? ‘CUXJ’

- W (23) ? C (3): +6

- O (15) ? U (21): +6

- R (18) ? X (24): +6

- D (4) ? J (10): +6

- Actually, letters are shifted forward by 6 in the alphabet.

- Let's try 'MOKE' ? ‘SUQK’:

- M (13) ? S (19): +6

- O (15) ? U (21): +6

- K (11) ? Q (17): +6

- E (5) ? K (11): +6

So, the code is: Each letter is shifted 6 places ahead.

Apply that to 'IDEA':

- I (9) ? O (15)

- D (4) ? J (10)

- E (5) ? K (11)

- A (1) ? G (7)

So, ‘IDEA’ = OJKG

Let’s check the options:

1. OJKG

2. OJLG

3. OJLH

4. OJMG

The correct answer is option 1: OJKG.