I think it is C, though not sure. Hope this helps you.
Natural Selection: Naturally, living organisms produce offspring that will inherit characteristics that give that offspring higher and most successful chances of survival. So offspring are naturally born with traits that suits them best for survival. Natural Selection process also consist of in comparison of living organisms, those who adapt best to their environment and have flexible characteristics survive longer than those who don't.
C) when the length of day and the length of night are the same
Explanation:
Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar
Explanation:
La energía es Consumidor como Animales y Plantas utiliza la energía para los procesos de la vida y se trasforma en Calor