Im not 100 percent sure, but I believe that the answer is D) because A), B), and C) are all equally necessary. Yet D) seems to have a much higher level of importance
C)set maximum contaminant levels for pollutants in drinking water
The correct sequence of events is : C,D,B,A.
Iron rich magma in the earth's core heats up because of radiation and the pressure exerted by the other layers of the earth. This heat in the crust trigger convection currents in the mantle. The magma closest to the core will be hotter and therefore less dense than other layers. Being less dense the layer will rise towards the crust, eventually becoming cooler and sinking back down in a circular motion.
The continued circular motion creates electric currents which then generates the magnetic field.
Nucleus.
Genetic material.
A plasma membrane.
Ribosomes.
Cytoplasm, including the cytoskeleton.
