Explanation:

- To find the rightmost non-zero digit of \(30^{30}\), we start by simplifying the problem.

- The expression \(30^{30}\) is \(3^{30} \times 10^{30}\).

- The digit we seek is in \(3^{30}\), since \(10^{30}\) is just trailing zeros.

- The pattern of last digits in powers of 3 is periodic: 3, 9, 7, 1.

- The cycle length is 4. So, for \(3^{30}\), find the remainder of 30 divided by 4, which is 2.

- From the pattern, the second number is 9.

Option:4 - 9 is correct.