All of the Following Are Aspects of a Cell's Ability

All of the following are aspects of a cell's ability to regulate its metabolism EXCEPT:

A) isolation of various enzymes within membranous organelles.
B) synthesis of a catabolic enzyme only when its substrate is available.
C) using the same coenzymes for anabolic and catabolic reactions that share substrate molecules.
D) synthesis or degradation of membrane transport proteins.
E) using the most energy- efficient energy source available.