Final answer:
Rob will create a total of 3 back promotion records: one each for dev1, dev2, and dev3 when he clicks 'Back Promote and Deploy', assuming that each environment receives a single promotion record for any number of user stories.
Step-by-step explanation:
The question pertains to the process of back promoting user stories (US) from a User Acceptance Testing (UAT) environment to development environments in order to minimize sandbox (SB) discrepancies. Rob needs to back promote a total of 5 tested user stories. The distribution of the back promotion is such that 1 user story goes to dev1, 2 to dev2, and 2 to dev3. When Rob clicks 'Back Promote and Deploy', the process will likely create individual promotion records for each environment the user stories are being promoted to.
Therefore, a total of 3 back promotion records should be created: one for dev1, one for dev2, and one for dev3. There will not be individual promotion records for each user story, rather each environment will have a single record representing the promotion of one or more user stories to that environment. However, specific processes may vary depending on the tools and workflows being used. Without specific contextual information about the system Rob is using, this is the most logical assumption.