To solve this problem, let's consider the possible prime numbers that can be distributed among the children. Prime numbers less than 18 are: 2, 3, 5, 7, 11, 13, and 17.

Let's start distributing the candies among the children using these prime numbers:

1. Distributing 2 candies:
- We can give 2 candies to 1 child and keep the rest for the other children. This can be done in 8 ways, as we have 8 children.

2. Distributing 3 candies:
- We can give 3 candies to 1 child and keep the rest for the other children. Again, this can be done in 8 ways.

3. Distributing 5 candies:
- We can give 5 candies to 1 child and keep the rest for the other children. This can be done in 8 ways.

4. Distributing 7 candies:
- We can give 7 candies to 1 child and keep the rest for the other children. This can be done in 8 ways.

5. Distributing 11 candies:
- We cannot distribute 11 candies among the 8 children as it exceeds the total number of candies available.

6. Distributing 13 candies:
- We cannot distribute 13 candies among the 8 children as it exceeds the total number of candies available.

7. Distributing 17 candies:
- We cannot distribute 17 candies among the 8 children as it exceeds the total number of candies available.

Therefore, the total number of ways to distribute the candies such that each child receives a prime number of candies is 8 + 8 + 8 + 8 = 32.

However, we need to consider that we have 18 identical candies, and in some cases, the distribution may result in the same number of candies for different children. For example, if we distribute 2 candies to one child and keep the rest for the other children, the same distribution can be achieved by giving 2 candies to a different child. Therefore, we need to divide the total number of ways by the number of identical candies.

In this case, since we have 18 identical candies, the final answer would be 32/18 = 28.

Hence, the correct answer is option C) 28.

28