The correct option is D Change in government stocks
The availability of food depends on three important factors: production of food in a year, net imports, and the change in government stocks. The production of foodgrains in a year refers to the net total production of foodgrains in a year. Countries import goods they need but do not produce sufficiently. Government stocks refer to the foodgrains procured from farmers, which are stored in state-owned granaries and distributed to people later.