Task: Class Definition Understanding (ontology: Earth_Environment/EnvironmentOntology)

Which of the following definitions best describes 'supraglacial lake'?

A. A lake which is primarily composed of oxic water.
B. A lake which is permanently covered by ice, does not mix, and exhibit inverse cold water stratification whereby water temperature increases with depth below the ice surface.
C. A water body which is located in a depression within the surface of a glacier.
D. A lake with medium nutrient levels, which allow moderate productivity.

Answer: A water body which is located in a depression within the surface of a glacier.