The stock of Grommet Corporation, a U. S. company, is publicly traded, with no single shareholder owning more than 5 percent of its outstanding stock. Grommet owns 95 percent of the outstanding stock of Staple Inc., also a U. S. company. Staple owns 100 percent of the outstanding stock of Clip Corporation, a Canadian company. Grommet and Clip each own 50 percent of the outstanding stock of Fastener Inc., a U. S. company. Grommet and Staple each own 50 percent of the outstanding stock of Binder Corporation, a U. S. company. Which of these corporations form an affiliated group eligible to file a consolidated tax return?