The right answer is B.Chris is right because some of the mass of the reactants escaped as gas. 
Sorry I'm late, but I hope I helped
 
        
             
        
        
        
The ozone layer helps prevent harmful UV rays from entering the atmosphere.
        
                    
             
        
        
        
The answer would be letter C.
        
                    
             
        
        
        
Answer:
Recessive lethal genes can code for either dominant or recessive traits, but they do not actually cause death unless an organism carries two copies of the lethal allele. Examples of human diseases caused by recessive lethal alleles include cystic fibrosis, sickle-cell anaemia, and achondroplasia.
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