Consider the actin proteins that are at the very ends of an actin filament. At one end the cleft region of the terminal actin protein is exposed and the hinged region is bound to the adjacent actin protein in the filament; whereas, at the other end the hinge region of the terminal actin protein is exposed and the cleft region is bound to the adjacent actin protein in the filament. Which region of the terminal protein is exposed at the minus end of an F-actin filament? Group of answer choices A. The cleft region B. The hinge region