The best statement that describes what will be observed in this experiment is:
D. Heat will flow from the iron block to the water until both reach a temperature somewhere between 50 degrees Celsius and 250 degrees Celsius.
In this scenario, the iron block, being at a higher temperature (250 degrees Celsius), will lose heat to the water, which is at a lower temperature (50 degrees Celsius), until thermal equilibrium is reached. The final temperature will be between the initial temperatures of both the iron and the water, but not exceeding the initial temperatures.