Despite what some people believe, i.e. that since we do not have direct access to the distant past we cannot learn much about it, contemporary historians and archaeologists find current geography, geology and climate to be rich in clues about a given region's distant history. We are, however, given the principle: "the more distant the period we are studying is, the less useful the study of the present becomes."
Answer choice (A) conforms closely to the principle above. Astronomers, like the contemporary historians and archaeologists of the passage, draw inferences from the past based on data from the present. However, there is little they can gather from preset data about the origin of our solar system, i.e.e a very distant point in the past.
Thus, answer choice (A) conforms to the principle that even though we can use info from the present to make inferences about the distant past, the more distant the period we are studying is, the less useful the study of the present becomes.
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