Cloud Kicks has been tracking how many participants wear the company's shoes in each marathon.

Cloud Kicks has been tracking how many participants wear the company's shoes in each marathon. The administrator creates two custom objects: Races and Runners. There is a master-detail relationship between them as well as a Roll-up Summary field on the Races object to show the count of runners in each race. Requirements have changed, and the administrator wants to delete the Master-detail Relationship field without deleting the Runners records.

What action should an administrator take before the Relationship field can be deleted?