Final answer:
The correct word for an extreme shortage of food is 'famine'. It describes a situation where food is not available in sufficient quantities to meet the needs of a population.
Step-by-step explanation:
The word that best fits the definition of an extreme shortage of food is famine. Famine occurs when there is a severe lack of food in a region, leading to starvation, widespread malnutrition, and increased mortality. While drought refers to a prolonged period of insufficient rainfall leading to a shortage of water, and scarcity refers to the limited nature of resources in general, the term famine specifically describes a crisis situation where there is not enough food available to meet the needs of the population.