If an agile development team has already been doing testing during each sprint, why should they consider using parallel independent testing?

1. Software developers are not trained to perform tests

2. Testing may sometimes be omitted from a sprint if the team runs out of time

3. The testing during a construction sprint does not happen in a production environment that simulates the conditions that customers will encounter

4. To identify potential defects that have fallen through the cracks

5. The defects found by independent testing are submitted to the continuous engineering team