A(n) includes all living and nonliving things in an environment. a. community b. ecosystem c. population d. landform

Don't understand how this was particularly hard; I feel people are just lazy.

The answer is ecosystem.
This is because c refers to a single animal or species. (i.e. population of wolves in said ecosystem.)
Community would be specifically the animals living in an area.
And a landform is the natural feature of a solid surface.

Nimbostratus is the correct answer.
explanation: nimbostratus clouds are the type of clouds that are mostly likely present on gray, rainy day. these clouds produce continuous rain, snow and there is no thundering or lightening either.