Tests are prioritized so that:

Prioritizing tests is an essential part of the testing process, especially when time and resources are limited. By prioritizing tests, teams can focus on the most critical areas of the application that have the highest impact on the overall quality and reliability of the product. This ensures that the best possible testing is performed within the available time frame.

When tests are prioritized thoughtfully, it allows teams to identify and execute the most important tests that will yield the most valuable feedback on the software's quality. This means that even if not all tests can be executed, the most pertinent and high-risk areas are covered first, leading to a better overall understanding of the product's status and readiness for release.

The other choices, while related to the benefits of prioritization, do not encapsulate the primary reason for prioritizing tests as effectively as doing the best testing in the time available. Other options suggest an increase in time efficiency, effectiveness, or fault finding, but they do not highlight the core objective of ensuring thorough testing given the constraints present.