Final answer:
Active transport is the best type of cell transport for moving substances into or out of the cell quickly.
Step-by-step explanation:
If the goal is to move substances into or out of the cell quickly, the best type of cell transport would be active transport. Active transport requires the cell to use energy, usually in the form of ATP, to move substances against their concentration gradient. This means that substances are moved from an area of lower concentration to an area of higher concentration. Active transport mechanisms can move small-molecular weight materials like ions, as well as larger molecules. Examples of active transport include pumping substances like K+ and Na+ across the cell membrane.