Which of the Following Is True for the Mechanism of the 2Na⁺/glucose

Which of the following is true for the mechanism of the 2Na⁺/glucose symporter?

A) Binding of 2 Na⁺ to the symporter open to the outside of the cell allows a glucose molecule outside the cell to bind.
B) Binding of Na⁺ and glucose causes the symporter to open to the inside of the cell.
C) Release of 2 Na⁺ ions to the inside of the cells causes release of the glucose molecule.
D) Binding of 2 Na⁺ to the symporter on the inside of the cell causes the symporter to open to the outside of the cell and release of the Na⁺ ions.
E) All of the above are steps in the mechanism.