Answer:
a. red-brown
Explanation:
Specular Hematite is a mineral which is found in rocks and soils. The crystal of specular hematite is greyish black in color but it can form the streak of reddish color which is due to the presence of iron oxide. It has metallic luster which gives a look like silver and has shiny flakes.
 
        
             
        
        
        
This is called species richness
        
                    
             
        
        
        
Carbon neutral is a term used to describe carbon-based fuel that when burned will not increase carbon dioxide in the atmosphere. these fuels neither contribute to nor reduce the amount carbon so the carbon will remain the same.
so I think carbon neutral is good for the environment but not us humans