Answer:
D
Step-by-step explanation:
Heat is a form of energy which can be transferred from a hotter region or body to another body.
As the red hot iron is dropped into the cold water . The temperature of the water will start to increase while that of the object will reduce since the iron is at a higher temperature. As soon as the temperature of both iron and water are the same, there will be no heat transfer from iron to water anymore. The temperature of the water will start dropping as heat will be lost from the water in the bucket to the surroundings.