Explain how farming changed with the Bantu migration.

The correct answer is **C. The Bantu brought advanced iron tools and new crops such as cereal grains to the new regions they settled.**

### Explanation:

The Bantu migrations, which took place over several centuries beginning around 1000 BCE, involved the movement of Bantu-speaking peoples from their original homeland in West Africa to other parts of the continent, particularly Central, Eastern, and Southern Africa. This migration significantly impacted agriculture in the areas they settled.

1. **Advanced Iron Tools**: The Bantu were skilled in ironworking and brought with them advanced techniques for making iron tools and weapons. These tools improved farming efficiency, allowing for more effective clearing of land, planting, and harvesting.

2. **New Crops**: The Bantu also introduced new agricultural practices and crops, including various cereal grains (such as millet and sorghum), as well as root crops like yams. The introduction of these new crops diversified local diets and improved food security in the regions they invaded and settled.

Overall, the Bantu migrations resulted in the spread of agriculture across large areas of Africa, leading to increased population densities and the development of complex societies.