The phosphotransferase system is classified as a form of active transport because Choose one: A. energy for the membrane transporter is provided by the electron transport chain. B. it requires energy to chemically modify the transported solute. C. ATP is hydrolyzed to effect a conformational change in the solute as it enters the cell. D. energy from the proton motive force is expended to bring the solute into the cell. E. energy is in fact not required, because the solute is not being moved against its concentration gradient.