How do the authors develop the central idea? by describing the controversy surrounding GMO foods by describing the controversy surrounding GMO foods by explaining the effects of GMO foods on the farming industry by explaining the effects of GMO foods on the farming industry by elaborating on the growing consumer demand for GMO foods by elaborating on the growing consumer demand for GMO foods by contrasting GMO foods with plants that are not genetically altered by contrasting GMO foods with plants that are not genetically altered