Final answer:
In Agile software development, it is reasonable to start the first Sprint with the available information and incrementally update the Product Backlog. Regular reviews and updates ensure the team is working on the most valuable features.
Step-by-step explanation:
The Product Owner's suggestion to start the first Sprint with the available information is a reasonable approach in Agile software development. Agile methodology encourages iterative and incremental development, which means that the team can start working on the available requirements and refine the backlog as they progress.
However, it is important to note that the Product Backlog should be regularly reviewed and updated based on feedback and changing priorities. This ensures that the development team is working on the most valuable and relevant features.
Therefore, option 2) Yes, it's a reasonably good time to start the first Sprint, is the best choice.