Final answer:
The correct answer is (b) There are problems not only with the children and their parents. 'Not only' is used to indicate that there are problems not just with the children and their parents, but with something else as well.
Step-by-step explanation:
The correct answer is (b) There are problems not only with the children and their parents.
The use of 'not only' indicates that there are problems not just with the children and their parents, but with something else as well.
In this sentence, 'not only' is used as a way to introduce additional information and emphasize that there are multiple sources of problems.