The correct experimental setup to investigate the connection between kinetic energy and temperature would be:
Placing one drop of food coloring in a cup with 50 mL of water at 10ºC; placing one drop of food coloring in a second cup with 50 mL of water at 40ºC.
This setup allows the student to observe the difference in diffusion rates of the food coloring in water at different temperatures. Higher temperatures generally correspond to higher kinetic energy of the water molecules, which would result in faster diffusion of the food coloring in the warmer water compared to the cooler water.