The digit by which * should be replaced in 54 * 281 so that the number formed is divisible by 9 is

1. 6

2. 7

3. 8

4. 9

For divisibility by 9, the sum of digits must be divisible by 9.

Sum of given digits (except *) = 5 + 4 + 2 + 8 + 1 = 20.

We need 20 + * to be divisible by 9.

20 + 7 = 27, which is divisible by 9.

So, * = 7.

Hence, option 2 is the correct option.