the answer is b because sedimentary rock can change into metamorphic rock or into igneous rock which metaraphic to ignouans or sedmintary rock hope this help tell me if it is right and can i have a brainliest if this answer is right
 
        
                    
             
        
        
        
Unburned hydrocarbon on reacting with oxygen undergoes combustion reaction. However, the activation energy of this reaction is significantly high. When a catalyst like Pd is added to the reaction system, it provides active sites for the reaction to occur. It acts are a heterogeneous catalyst. It is pertinent of note that catalyst is refereed as heterogeneous, when it exist in different phase as compared to reactant and products. In present case, reactants and products are in gas phase, while catalyst is in solid phase. Due to availability of larger surface area at active site of Pd, activation energy of reaction decreases and decrease in activation energy favors higher reaction rates. 
        
             
        
        
        
The opportunity costs of working part-time while attending high school could be studying time, grades, and your own free time. It depends on the person, how they do in school, but if it were for me, I would say the benefits outweigh the costs. I have enough time to study and still get good grades in school.
 
        
                    
             
        
        
        
The units of ppm means parts per million. Also, It is equivalent to milligrams per liter. It is one way of expressing concentration of a substance. It u<span>sually used to describe the concentration of something in water or soil. We calculate the mass of CaCO3 as follows:
Mass = 75 mg/L (.050 L) = <span>3.75 mg CaCO3</span></span>