Traditional theories suggest that human ancestors were forced to leave the arboreal environment and chose to walk upright on the ground due to climate change and reduced trees. A new study suggests that early human upright walking originated from the rugged mountains of eastern and southern Africa today. The terrain was formed by a volcanic eruption and tectonic plate movement during the Pliocene period. Human ancestors were attracted by rocky terrain and canyons, which can provide good shelter habitats and opportunities to trap prey; this environment required early humans to stand The ability to walk and climb, so human ancestors eventually evolved into bipedal upright walking. Which of the following is consistent with the conclusions of the latest study? ['Climate change led early humans to choose to walk upright.', 'Human ancestors chose to walk upright to better adapt to the terrain environment.', 'Changes in geological conditions changed the way early ancestors of humans walked.', 'Human ancestors were forced to leave the original living environment due to lack of food.']