Which statement best describes a characteristic of an ecosystem

An ecosystem is a geographic area where plants, animals, and other organisms, as well as weather and landscape, work together to form a bubble of life. Ecosystems contain biotic or living, parts, as well as abiotic factors, or nonliving parts. Biotic factors include plants, animals, and other organisms.Most ecosystems characteristically possess a well-defined soil, climate, flora and fauna (or communities) and have their own potential for adaptation, change and tolerance. The functioning of any ecosystem involves a series of cycles, e.g., the water cycle and the cycles of various nutrients.

the real answer is b. scintillation counter

the supermassive black hole is in the middle of the galaxy.