about "fleet". It is used in some google documentation but could not find it in the console. I see "groups" and I see that you can create a groups that creates VM machines from a given template. As the templates also support a startup script, it may be the answer to the question.
Any ideas about the solution proposed in the video ?
I think that the options is used merely as distractor (trick question). AWS uses the term "Instance Fleet" or "EC2 Fleet", whereas as you pointed out, this is called "Instance groups" in GCP.