Answer:
2. Step 4 should be “Click Insert.”
Explanation:
This is the step that is missing in this description. Frank is mostly performing the right actions when it comes to attaching a file to an email. However, he is not following the right step to finalize. Step 4 should read "click insert" in order for the command to be finalized. Learning how to attach a file to an email is a very important skill that Frank would benefit from having.