D because they are complete systems
Answer:
So you need help? Mk....
Earth can be divided into three MAIN layers: the core, the mantle and the crust. Each of these layers can be further divided into two parts: the inner and outer core, the upper and lower mantle and the continental and oceanic crust. ... The inner core is solid, while the outer core is liquid.
Answer: what are you asking in this question?
Explanation: