What is one way the people in West Texas modified their environment in the 20th century? A) They introduced windmills and barbed wire to farms in the Mountains and Basins region around El Paso. B) They built airports, drilled for oil, and turned Midland and Odessa into new urban centers. C) They replaced farms with ranches in order to use all available land to raise cattle. D) They constructed new roads for out-of-state tourists visiting the Alamo.