I would go with c because its tells you right in there that the ecosystem help who lives around that area.
They both involve topics related to the natural world, and are both based on empirical evidence. <span />
A convergent boundary is an area on Earth where two or more lithospheric plates collide. One plate eventually slides beneath the other causing a process known as subduction. The subduction zone can be defined by a plane where many earthquakes occur, called the Benioff Zone.
Surface tension decreases when temperature increases because cohesive forces decrease with an increase of molecular thermal activity
Proteins are a type of Macromedia and is made up of sub units that are called amino acids.