The correct option is D Concentration of Nucleic Acids
Factors that need to be homeostatically maintained are:
1) Concentration of Nutrient Molecules
2) Concentration of O2 and CO2
3) Concentration of Waste Products
4) pH level
5) Concentration of Water, salt and other electrolytes
6) Volume and Pressure
The concentration of Nucleic acid has no play in this.