The correct answer is option B, that is, they all use cellular respiration to obtain energy.  
Cellular respiration refers to a set of metabolic procedures and reactions, which occur in the cells of species to transform biochemical energy into ATP and then discharge waste products. The reactions taking place in respiration are catabolic, that is, dissociation of bigger molecules into smaller ones, and in the process liberating energy.  
The nutrients, which are generally utilized by plant and animal cells in the process of respiration are amino acids, sugar, and fatty acids, and the most usual oxidizing agent, that is, the electron acceptor is the molecular oxygen.  
 
        
             
        
        
        
Answer:plants
Explanation:
Every food chain begins with plants
 
        
                    
             
        
        
        
Answer:
Plants.
Explanation:
 Note: I may be wrong, if so, i am deeply sorry<3
 
        
             
        
        
        
Primary, so the first option, or option A
        
                    
             
        
        
        
Https://www3.epa.gov/climatechange/kids/impacts/effects/ecosystems.html
this link might help you