C1, C2, C3, C4, аnd C5 аre dоmestic cоrpоrаtions and Z is a publicly traded foreign corporation. Z owns 100% of C1 and 50% of C4. C1 owns 80% of C2 and 50% of C4. C2 owns 100% of C3. C4 owns 100% of C5. Which corporations qualify as an affiliated group for purposes of filing a federal consolidated income tax return?