[Solved] The naked mole rat lacks a circadian rhythm of activity. The ultimate adaptive significance of this point is that A) because naked mole rats live underground, they are not exposed to daily changes in light intensity and thus have no cues for the entrainment of a circadian rhythm. B) the environment of the naked mole rat is such that queens and kings gain no reproductive advantage by having a sterile work force that is active on a 24-hour schedule. C) naked mole rats are primitive mammals that do not have the sophisticated mechanisms that control circadian rhythms. D) naked mole rats do not have the genetic information that would enable them to develop a brain capable of circadian rhythms. Market Failure: A scenario where the distribution of goods and services through a free market fails to achieve efficiency, typically resulting in a decrease in overall social welfare. Public Goods: Goods that are non-excludable and non-rivalrous, meaning they can be used by everyone without diminishing availability to others, such as public parks and street lighting. Price Mechanism: The system by which the prices of goods and services are determined in a free market, through the forces of supply and demand. Government "Five-Year Plan": A centralized and often government-enforced economic development strategy, typically aimed at rapid industrialization or development within a five-year timeframe.