Explanation:

To find out the smallest natural number to add to 54321 to make it divisible by 6:

- A number is divisible by 6 if it is divisible by both 2 and 3.

- Condition 1: For divisibility by 2, the last digit should be even. (54321’s last digit is 1, and adding 1 (Option 3) makes it even).

- Condition 2: For divisibility by 3, the sum of digits should be divisible by 3. The sum of 54321’s digits is 15. Adding 3 (Option 2) makes total digit sum 18, which is divisible by 3.

Adding 3 satisfies both conditions, making the total divisible by 6.

- ?? Correct Answer: Option 2 - 3