Final answer:
The movement of a solution from a lower to a higher concentration across a membrane, known as active transport, requires energy.
Step-by-step explanation:
The scenario that requires an input of energy to occur is: B. The movement of a solution from a region of lower concentration on one side of a membrane to a region of higher concentration on the other side. This process is known as active transport, and it involves the movement of substances against their concentration gradient. In contrast, osmosis and other forms of passive transport, such as simple diffusion and facilitated diffusion, allow substances to move from areas of higher concentration to areas of lower concentration without the need for energy.