The hydrosphere, lithosphere, biosphere, and atmosphere are all examples of a) open systems b) closed systems c) biological systems d) ecosystems

I think its A. Open systems

D) ecosystems.  

Explanation:

The hydrosphere, lithosphere, biosphere, and atmosphere are all the examples of an ecosystem.

Basically, ecosystem includes all of the living organisms like plants, animals, and organisms which are exist in all the earth's sphere like atmosphere(air), lithosphere(land), biosphere(living things) and hydrosphere(water).

These spheres are closely connected to each other. For example:

Many birds (biosphere) fly through the air (atmosphere), While water (hydrosphere) flows through the soil (lithosphere).

i think the answer would d