What type of transport does not require energy?

The option identified is correct because passive transport refers to the movement of substances across a cell membrane without the need for energy input from the cell. This process occurs naturally due to the concentration gradient, where molecules move from an area of higher concentration to an area of lower concentration until equilibrium is reached.

Passive transport includes various mechanisms, such as simple diffusion and facilitated diffusion, both of which rely on the innate kinetic energy of molecules rather than cellular energy. In contrast, active transport requires energy, typically in the form of ATP, because it involves moving substances against their concentration gradient, which is an energy-intensive process. Exocytosis also consumes energy to transport materials out of the cell by vesicle fusion with the cell membrane. Thus, passive transport stands out as the method that does not need energy, relying solely on the natural movement of molecules.