A secure chemical landfill is a carefully engineered depression in the ground (or built on top of the ground, resembling a football stadium) into which wastes are put. The aim is to avoid any hydraulic [water-related] connection between the wastes and the surrounding environment, particularly groundwater.
Explanation:
Sea otters are an iconic species, representing the beauty and diversity of marine life found along California’s coastline. They’re also considered a keystone species because of their critical importance to the health and stability of the nearshore marine ecosystem. They eat sea urchins and other invertebrates that graze on giant kelp.
Im pretty sure it is C because all living things consist of at least one or more cells