People widely believed that the controlled use of fire originated 200, 000 years ago with the human species Homo sapiens. However, a site containing a deposit, estimated to be nearly 500, 000 years old, consisting of charcoal, burned animal bones, and charred rocks, has recently been found. Although homo sapiens did not exist at that time, this discovery provides no basis to the claim that the controlled use of fire preceded the Homo sapiens, since __. Which of the following most logically completes the passage? ['It is possible that fire was used much earlier than 500, 000 years ago', 'The use of fire might have originated independently in several different parts of the world', 'It is impossible to determine whether a charred deposit dating from so long ago resulted from a fire caused by lightening or from the purposeful use of fire', 'Animal bones could have been discarded in a fire used for purposes such as protection or heat rather than for cooking']