Explanation:

Let’s break this code down step by step:

- 'DISK' becomes 'SIKD'. Here’s what’s happening:

- The first and second letters swap (D and I ? I and D).

- The last two letters swap (S and K ? K and S).

- Reordering: D I S K ? I D K S (but in the example, it’s SIKD? Wait...)

- Check 'MINE' and 'NIEM':

- The first pair swaps: M, I ? I, M

- The second pair swaps: N, E ? E, N

- Rearranged, we get NIEM. So, it’s a swap of first two, then last two.

Let’s apply this to 'BOLD':

- Take 'BOLD'

- First two letters swap: B O ? O B

- Last two letters swap: L D ? D L

- Put them together: O B D L

Now, review the options:

1. BLOD (Nope, unchanged order except for last two)

2. DOLB (Not matching above)

3. BDOL (First stays, only last two swapped)

4. LODB (No, this is just a different rearrangement)

Correct answer: NONE of the above strictly matches 'OBDL'.

But looking back, let's double-check the code. Maybe the pattern is:

- For 'DISK' ? 'SIKD':

- 2nd letter (I), 1st letter (D), 4th letter (K), 3rd letter (S)

So, mapping: 2 1 4 3

- For 'MINE' ? 'NIEM':

- 2nd (I), 1st (M), 4th (E), 3rd (N): 2 1 4 3

Apply same to 'BOLD':

- 2nd letter (O), 1st letter (B), 4th letter (D), 3rd letter (L) ? OBDL

Your options:

- Option 1: BLOD (No)

- Option 2: DOLB (No)

- Option 3: BDOL (No)

- Option 4: LODB (No)

Looks like there isn't an OBDL in the given options. But if the instruction is to choose from above, and LODB is the closest by pattern, but actually, according to our decoding, none match.

Here’s what you should remember:

- Both samples follow the 2 1 4 3 pattern.

- The correct code for 'BOLD' is 'OBDL', but it's not an option.

- Of the choices, none capture the right pattern, but the existing pattern doesn’t support any of the options.

So the answer is: None of the options match the code.

But per actual code, the answer would have been OBDL