How is Earth's hydrosphere and geosphere
(its solid material) interact as a river forms and ages

The hydrosphere, including all the waters on the Earth’s surface, is interconnected with the other ‘spheres’ in the Earth system, that is the geosphere (lithosphere and atmosphere), the biosphere, and the human-related anthroposphere. Water, the most widespread substance in the environment of our planet, is available, in liquid, solid, and vapor states, everywhere on Earth, albeit its abundance largely differs in space and time. Quantitative estimates of availability of water (and in particular, freshwater) in different Earth’s water stores (reservoirs) are given.

Explanation:

b.europe i believe because north america has 3 countries in a way and with all the stuff with illegal immagrants from mexico or whatever so i would say europe.

answer; i believe the answer is (mesopotamia); modern day