The answer is the option d. metabolism.
Metabolism is the set of the chemical reactions that happens in the organism to transform nutrients (food) in energy and the products that conform the cells and all the constituents of the body.
Answer & Explanation:
Los electrones externos se encuentran más lejos del núcleo. El número de electrones en la capa más externa (electrones de valencia) de un átomo en particular determina su reactividad (tendencia) a formar enlaces químicos con otros átomos.
Los electrones internos son los más cercanos al núcleo. Protegen los electrones de valencia del núcleo, reduciendo la carga nuclear efectiva.
The answer is the third one .
A controlled variable is the one that is kept constant, the manipulated variable is the independent variable in an experiment , it is called manipulated because is the one that can be changed. A responding variable or variables are the dependent variables that change as a result of the changes in the manipulated variable.