Movement into and out of cells — practice question

Which statement is the definition of active transport?

• Amovement of large molecules through the cell surface membrane into the cytoplasm of a cell
• Bmovement of molecules or ions from where they are in a low concentration to where they are in a higher concentration
• Cmovement of molecules or ions from where they are in a high concentration to where they are in a lower concentration
• Dnet movement of water molecules across a partially permeable membrane from a region of higher water potential to one of lower water potential