A usable water source is one that can be used by humans for drinking or agriculture. Identify the water reservoirs as usable or unusable based on their current state.
Usable source:
Unusable source:
A:oceans
B:rivers
C:glaciers
D:freshwater lakes
E:groundwater
Usable source: B: rivers, D: freshwater lakes, E: groundwater
Unusable source: A: oceans, C: glaciers