When creating and managing custom actions in an enterprise setting, which of the following is considered a best practice?

Which of the following commands will set the $FOO environment variable within a script, so that it may be used in subsequent workflow job steps?

Scheduled workflows run on the:

As a developer, you need to create a custom action written in Python. Which action type should you choose?
As a developer, you need to create a custom action written in Python. Which action type should you choose?

A development team has been using a Powershell script to compile and package their solution using existing tools on a Linux VM, which has been configured as a self-hosted runner. They would like to use the script as- is in an automated workflow. Which of the following should they do to invoke their script within a workflow step?