Explanation:

- The original equation is 12 ÷ 2 × 6 + 4 - 2 = 13.

- Option 1 suggests swapping × and -, changing it to 12 ÷ 2 - 6 + 4 × 2. This calculation is 6 - 6 + 8 = 8, which is incorrect.

- Option 2 suggests swapping × and +, changing it to 12 ÷ 2 + 6 × 4 - 2. This calculation is 6 + 24 - 2 = 28, which is incorrect.

- Option 3 suggests swapping + and ÷, changing it to 12 + 2 × 6 ÷ 4 - 2. This calculation is 12 + 3 - 2 = 13, which is correct.

- Option 4 suggests swapping + and -, changing it to 12 ÷ 2 × 6 + 2 - 4. This calculation is 36 + 2 - 4 = 34, which is incorrect.