Answer: A way of using your creativity to develop new ideas and solutions to problems.
Explanation: The process is based on separating divergent thinking styles, so that you can focus your mind on creating at the first stage, and then evaluating at the second stage.
The answer, in my opinion, is the second sentence, "The coach who is an expert in the sport explained the revised rules to us". Here, the "Who is an expert", is presumably the nonessential clause.