The maintenance of a living system requires a:

Explanation

The correct answer is Option B: continual supply of free energy. Living organisms require a steady and ongoing influx of energy to support vital processes like growth, reproduction, and environmental response. Without this continuous energy supply, these life-sustaining processes would halt, leading to the organism's demise. Option A fails to emphasize the necessity for constancy in the energy supply. Option C is incorrect because it suggests a need for progressively more energy, which is not typical for living organisms. Option D is incorrect, as a decreasing energy supply would lead to detrimental effects on the organism's health.