Movement into and out of cells — practice question

Agar cubes may be used to show how diffusion is affected when the surface area to volume ratio changes. Three different agar cubes, prepared using a coloured indicator solution, were placed in a dilute acid which diffused into the cubes. As the acid spread through the agar cubes, the indicator solution changed colour. The cubes had volumes of $1\ \text{cm}^3$, $2\ \text{cm}^3$ and $3\ \text{cm}^3$ and were kept in the dilute acid for $10$ minutes. All the other variables were kept constant. After $10$ minutes, the agar cubes were taken out of the dilute acid and sliced in half. The cut surfaces were examined and the outcomes were recorded as diagrams. All diagrams were drawn to the same scale. The results for the $2\ \text{cm}^3$ cube are shown. Which diagrams show the results for the $1\ \text{cm}^3$ and the $3\ \text{cm}^3$ cubes?