Graph Analysis: In the provided graphs, each graph represents the status of defects over time, divided into categories: Open, Fixed, and Tested and Closed.

Option A: Shows a large number of open and fixed defects with fewer tested and closed defects.

Option B: Indicates an increasing trend in tested and closed defects but still has a substantial number of open defects.

Option C: Shows a significant decrease in open defects and a substantial increase in tested and closed defects, indicating progress.

Option D: Depicts the fewest number of open defects, with the majority of defects tested and closed, indicating that most defects have been addressed and verified.

Conclusion: The graph in Option D, with the majority of defects tested and closed and the fewest number of open defects, suggests the product is most ready for formal release to the customer. This aligns with software quality assurance principles where minimal unresolved defects indicate readiness for release.