Here's a problem to solve: Ice will form on small ponds when the temperature drops below 0°C. Which property of ice is most beneficial to fish living in these ponds?

Among the 4 following options, which is the correct answer?

- A: Ice has a temperature colder than the temperature of water.
 
- B: Ice absorbs sunlight that is reflected by water.
 
- C: Ice traps more pollution than is trapped by water.
 
- D: Ice had a density lower than the density of water.
 