The Earth is a unique planet in that it is covered by more than 70 percent water. There are several properties of water that make Earth a suitable environment for life, including how the density of solid water (ice) is about nine percent less than the density of liquid water. Which best explains why this feature of water is important for marine life?

Ice forms from the bottom of the water column up, allowing organisms to freeze and enter hibernation.
Ice forms from the top of the water column down, creating a protective barrier over the liquid water.
The higher-density liquid water shelters organisms from cold air better than the less-dense ice.
The higher-density liquid water traps nutrients for primary producers better than the less-dense ice.