[Solved] If total liabilities increased by ¥21,000 during a period of time and equity decreased by ¥9,000 during the same period, then the amount and direction of the period's change in total assets is a(n) A)¥21,000 increase. B)¥30,000 increase. C)¥12,000 decrease. D)¥12,000 increase. Food Supply: The provision and availability of food materials to organisms, ensuring their nourishment and survival. Social Structure: The organized pattern of social relationships and social institutions that together constitute society. Naked Mole Rats: A species of hairless rodents known for their longevity, resistance to cancer, and ability to live in highly social, cooperative colonies underground. Social Insects: Insects that live in organized colonies and exhibit complex behaviors such as division of labor, cooperation, and the ability to solve problems as a collective.