Answer:
The answer is B producing oxygen
Explanation:
 
        
                    
             
        
        
        
The cardiovascular system transports oxygen and nutrients to the cells and transports waste away from the cells
        
             
        
        
        
Depends in the weight of tge objects, but they will be drawb together
        
                    
             
        
        
        
Double layered nuclear, the outer nuclear membrane is continuous with the membrane of the rough endoplasmic reticulum (ER), it also continues with the inner nuclear membranes since the two layers are fused together at a numerous tiny holes called nuclear pores that perforate the nuclear enevelope