Final answer:
The glucose-Na+ symport in epithelial cells uses the electrochemical gradient of Na+ to draw glucose into the cell. Hence the correct answer is option A
Step-by-step explanation:
Symport mechanisms move two or more substances in the same direction at the same time, whereas antiport mechanisms move two or more substances in opposite directions across the cell membrane. One example is the sodium-glucose symporter in epithelial cells. This symporter uses the electrochemical gradient of sodium to draw glucose into the cell. The flood of sodium ions through the symporter provides the energy that allows glucose to move through the symporter and into the cell, against its concentration gradient.
Hence the correct answer is option A