Answer:
The answer is A. a tissue 
Explanation:
Tissues are groups of similar cells that have a common function. An organ is a structure that is composed of at least two or more tissue types and performs a specific set of functions for the body.
 
        
             
        
        
        
Im thinking its D. bcuz all three A. B. C. are true
        
                    
             
        
        
        
A:True. B:True. hope this helps
        
                    
             
        
        
        
the <em>sun's corona</em> is only visable when there is a solar eclipse