Read the passage.

Carver's Creative Crops
Cotton was once the main cash crop of the southern United States, its cultivation and sale providing a reliable income for farmers. In the early 1900s, however, the South suffered a widespread infestation of boll weevils (beetles that feed on cotton), which annihilated cotton crops. Many farmers were plunged into poverty, no longer able to eke out a living from cotton. George Washington Carver, an agriculture professor at Alabama's Tuskegee Institute, addressed this situation by promoting crop diversification. He particularly advocated the cultivation of peanuts as a cash crop because they were easy to grow and had properties that helped replenish the cotton-depleted soil. As part of his campaign, Carver developed many unexpected peanut-based recipes, such as peanut carrot fudge and peanut soup. His innovations went well beyond the culinary, however: Carver also developed peanut-based soap, face powder, axle grease, printer's ink, and numerous other products. Peanut cultivation in the South increased rapidly, and the economy improved.
What is the main, or central, idea of the passage?

The central idea of the passage is that George Washington Carver promoted crop diversification, specifically the cultivation of peanuts, as a solution to the widespread devastation of cotton crops caused by boll weevils in the southern United States. Carver's efforts not only helped replenish the depleted soil but also led to the development of various peanut-based products, leading to an improvement in the economy.

The main, or central, idea of the passage is that George Washington Carver promoted crop diversification in the southern United States, particularly advocating the cultivation of peanuts as a cash crop to overcome the devastation caused by boll weevil infestation and replenish the cotton-depleted soil.