A. Nutrients, vitamins would also be a correct answer
Genes are responsible for every cellular differences in a way that it is active on the same type of cell and inactive in another type of cell. The reason for genes to be active in a specific cell is because of enzymes or protein that turn it on.
This is called your manipulated variable or independent variable. If graphing, make sure to plot these points using you x-axis.
Well one result to the malfunctioning of a liver would be the build up of toxins which could be harmful.
Hope this helped out!!!!!! :D