Apply the principles of diffusion to explain what will occur after placing a dyed sugar cube in a beaker of water

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.

the correct answer is c   with the systems

is this a psat question, if so do not cheat try your best.