1. C. a species evolves at a slow, steady pace.
Gradualism, is the process by which a certain specie or creature undergo changes and variations in a limited and solely focusedly confined in long period of time.
2. A. A disease kills off a single species of predator within an ecosystem.
Mass extinction is a massive and global elimination in a certain specie or species. It doesn’t involve itself only in a secured and measurable area but it impacts the whole large-scale of population as a whole.