The Product Owner’s job is to be the customer or the customer proxy. He needs to know the most current information about the product and the business that the team is working in. If this is the case, then the Product Owner is able to make relevant choices about the product and will be able to answer the questions of the team. If this is not the case, then he will have to find someone else for the answers (which will cause waste), make up the answers (which will likely guide the team in the wrong direction), or fail to give the team what they need.
To learn more about your Product Owner, visit the Scrum Team Assessment.