Answer:
Option D, Zinc is higher on the activity series because there is clear evidence of a reaction.
Explanation:
It is very clear that a metal which is higher in activity will replace a metal having lower activity.  
Since, Zinc has higher activity than copper, it is very sure that it in a copper chloride solution it will replace copper and produce zinc chloride solution leaving behind copper as residue.  
Residues of copper is a clear evidence of reaction  
The chemical equation for this reaction would be -
 
Hence, option D is correct
 
        
             
        
        
        
Changes in temperature, salt concentration, ionic concentration, of pH levels
        
             
        
        
        
<span>The Left-sided Problem of the heart involves the lack of enough supply of oxygen induced blood and the blood which is unable to reach the heart goes to lungs causing breath issues. Another issue with this problem is that left side of the heart pumps blood into the body, so when it fails, less blood will be pumped into the arteries.</span>
        
             
        
        
        
They are the same density. 
        
                    
             
        
        
        
The answer for your question is G2!