The end result of metabolism is a cellular energy unit called ATP. So the correct option in regards to the given question is option “d”. Metabolism is a process that helps in chemical transformations within the cells of all living organisms. Metabolism actually helps an organism to grow, reproduce, and respond to the changes in the environment and also to maintain their own structure. Metabolism can also be divided into two parts and they are anabolism and catabolism. Without metabolism it is not possible for any organism to survive.