Correct answer - "Create one customer managed policy with dynamic variables and attach it to a
group of all users" : This is the most efficient and best practice, because it's a "set and
forget" action.
Incorrect answers
"Create an S3 bucket policy and change it as users are added and removed" : This doesn't scale
and the S3 bucket policy size may be maxed out
"Create inline policies for each users as they are on-boarded" : This would work but doesn't
scale and it's inefficient.
"Create one customer managed policy per user and attach them to the relevant users" : This would
work but doesn't scale and would be a nightmare to manage.