Step 1: Membrane transporters are grouped by how many solutes they carry and in which direction. Uniporters carry a single solute, symporters carry two solutes the same way, antiporters carry two solutes opposite ways.
SGLT1 uses the downhill movement of Na+ into the cell to drag glucose in along with it, both moving inward together.
Since both solutes travel in the same direction, SGLT1 fits the symporter category exactly. Answer: Symporter.