Answer:
Water is the best insulator.
Explanation:
Specific Heat Capacity is the amount of heat required to raise the temperature of 1 kg of a substance by 1 K.
<em>A good insulator has a high specific heat capacity.</em>
This means that it absorbs more heat for raising its temperature by 1 K.
This is a property of a good insulator.
Among the given materials, water has the highest specific heat capacity.
Hence, water is the best insulator.