The correctly worded questions from your options that would lead to the answer "Il y a un livre" are:
- Est-ce qu'il y a un livre? (This is a correct and standard way to ask if there is a book.)
- Y a-t-il un livre? (This is also a correct and standard way to ask if there is a book.)
Both of these versions are grammatically correct in French.
So, the correct answers would be:
- Est-ce qu'il y a un livre?
- Y a-t-il un livre?