It is because of the differences in specific heats. The specific heat of water is much higher than that of lead. It takes more heat to raise water to a boiling point and keep it there than it takes lead to maintain a temperature of of 300oC.
It's all due to specific heat. The answer, though poorly worded, is the last choice.
Answer:
because water's specific heat is much greater than that of lead, therefore this amount of lead cannot contain as much heat.