The best statement that describes what will be observed in this experiment is:
Heat will flow from the iron block to the water until both reach a temperature somewhere between 50 degrees Celsius and 250 degrees Celsius.
This is consistent with the principle of heat transfer, where heat flows from the hotter object (the iron block at 250 degrees Celsius) to the cooler object (the water at 50 degrees Celsius) until thermal equilibrium is reached. The final temperature will be somewhere between the two initial temperatures.