To determine which option (A or D) contains a homogeneous solution based on the description of the diagram, we need to clarify what a homogeneous solution is. A homogeneous solution is one in which the composition is uniform throughout; that is, the particles are evenly distributed and not distinguishable from one another.
If you have access to a diagram showing the arrangement of the particles (the spheres in this case) and their shadings, you would need to identify whether there is a consistent distribution of the same type of particle across the entirety of the solution in either option A or D.
If option A has evenly mixed spheres of the same shading throughout, it would represent a homogeneous solution. Conversely, if option D has separate clusters of different shadings, it would indicate a heterogeneous solution.
Please review the diagram based on this criteria to determine which option is truly homogeneous.