It would be was and was because he is singular. I'm not sure about complete or completes, but I think it would be complete.
Answer: Prewriting. You're ready to start writing. ...
Writing. Now you have your plan and you're ready to start writing. ...
Revision. Your story can change a great deal during this stage. ...
Editing. You have overhauled your story. ...
Publishing.
Explanation:
P1 is the name of first seeds collected from <span>monohybrids</span>