1. Insulin signaling of glucose uptake leads to the formation of vesicles that _______. A. contain GLUT4 and fuse with the membrane to increase import of glucose. B. contain GLUT2 and fuse with the membrane to increase import of glucose. C. contain GLUT4 and fuse with the membrane to increase the export of glucose. D. contain GLUT2 and fuse with the membrane to increase the export of glucose