Explanation:

- Availability: Food must be available in sufficient quantities and consistently. It's about having enough food staples for the population.

- Accessibility: People must be able to obtain food physically and economically. This ensures that everyone can get the food they need.

- Affordability: Food prices must be reasonable, allowing people to buy as much as they need without financial strain.

- Acceptability: While important for personal and cultural reasons, acceptability isn't a core aspect of food security. Food security primarily concerns whether food is available, accessible, and affordable.

Correct Answer: Acceptability