The user has provided an image containing a physics problem and a graph. The question asks to determine the time it takes for a substance to completely transition into a liquid state, given that it was initially in a solid state, based on the provided temperature-time graph. The graph shows temperature on the y-axis (in °C) and time on the x-axis (in minutes). The substance starts at a low temperature, its temperature increases, then plateaus, then increases again, and finally plateaus at a higher temperature. The plateau where the temperature remains constant during heating indicates a phase transition. In this case, the first plateau (around 20°C) represents melting (solid to liquid), and the second plateau (around 40°C) would represent boiling (liquid to gas), if the graph extended that far. The problem states the substance was initially in a solid state and asks when it *fully* transitioned to a liquid state. This means we are looking for the time when the melting process is completed. Melting begins at the start of the first plateau and ends at the end of the first plateau. Observing the graph, the first plateau occurs at approximately 20°C. This plateau starts at time t=2 minutes and ends at time t=12 minutes. Therefore, the substance is fully in a liquid state after 12 minutes.