Most substances contract on freezing. However, water does not belong to this category. We know that water expands on freezing. Further, coefficient of volume expansion of water in the temperature range from `0^(0)C` to `4^(0)C` is negative and above `4^(0)C` it is positive. This behaviour of water shapes the freezing of lakes as the atmospheric temperature goes down and it has an extremely important effect on plant and animal life in lakes.
If the atmospheric temperature is below `0^(0)C` :

Options

A. ice will from the bottom upward and the plants and animals in the lake will be displaced to the upper part of the lake
B. ice will form in a random manner throughout the volume of the lake and with the passage of time, different segments of ice will join together to result in a collective ice mass
C. ice will form from the surface downward and plant and animal life will survive in the water beneath
D. water in the lake does not freeze. Infact, water in the atomsphere freezes and falls into the lake and floats on the surface of lake as ice

Answer

C