Scientists analyzed and analyzed the fourth metatarsal fossil of the southern ancient ape foot bone excavated at the Hadar site in Ethiopia, and found that the southern ancient ape has regular arched feet. They think that human ancestors date back 3.2 million years ago. Just started walking on both feet like modern people. Which of the following, if true, would best support the above argument? ['Only by praying for the 4th metatarsal fossil can we find that the southern African ape has a shaped arched foot.', 'Only the southern ancient apes were human ancestors.', 'Walking with two feet is only possible with shaped arched feet.', 'Have arched feet only when walking with both feet.']