That would be 75% of Earth's atmosphere.
        
             
        
        
        
Answer: option d. the Missouri and Ohio Rivers.
Explanation:
During the last ice age, there was reduction in the amount of solar radiation that hits the surface of the erth. As a result of this, some continents experienced a glacial growth and cold climates and the geography was also affected.
North America was covered by ice and the mid-western North America, the southern boundary of the north polar ice cap during past ice ages is marked by Missouri and Ohio Rivers.
 
        
             
        
        
        
Answer:
It should be A, Asians (specifically Chinese)
 
        
                    
             
        
        
        
In the development of a terrestrial planet, the stage of differentiation when dense material settled to the core and less dense to the outer parts.  
The stage of planetary differentiation<span> includes separating out different constituents of a </span>planetary<span> body and development into compositionally distinct layers.
</span><span>It is the organization of the Earth into layers.</span>