I, seems to be the answer, because its not a sexual reproduction, (this occurs in cells, its not sexual reproduction, you would need the egg and sperm.
The molecules in the sugar move from an area of higher concentration (sugar cube) to an area of lower concentration in the water.
That is exactly what diffusion is: the net movement of molecules or atoms driven by a gradient , which means that it doesn’t requires energy.
Remember that a biotic factor is a living component in an ecosystem that affects the population of another organism. So that means that the answer is B.