Explanation
Correct answer: D.
Choice D is the best answer. Cooling magma would create basalt, but “a planetary surface that formed in a mostly basaltic environment would be unlikely to contain large amounts of silica.” Since Mars’s crust does contain large amounts of silica, it is unlikely that Mars’s crust was formed exclusively by cooling magma. Therefore, there were likely other major geological events that created the high silica concentrations.
Why the other choices are wrong
Choice A
Choice A is incorrect. Although the passage discusses these two methods of collecting data about Mars’s crust, it never compares their reliability, so there’s no basis for this inference.
Choice B
Choice B is incorrect. The passage never mentions anything about the crusts of other planets, so there’s no basis for this inference.
Choice C
Choice C is incorrect. The passage never mentions Earth’s crust, so there’s no basis for this inference.