Question ID:PT90 S2 Q17 Passage:To establish a human colony on Mars would involve assembling tremendous quantities of basic materials at the site of the colony. But because the costs of transporting such materials through space would be so high, it will not be economically feasible to colonize Mars. Stem:Which one of the following is an assumption required by the argument? Correct Answer Choice:EChoice A:Only if the cost of transporting materials from Earth to Mars decreases will human habitation be established on Mars. Choice B:The cost of transporting basic materials through space is not expected to decrease in the near future. Choice C:Earth is the only source of the basic materials that would be needed to establish human habitation on Mars. Choice D:No significant benefit would result from establishing human habitation on Mars. Choice E:Mars is not a practical source of the basic materials required for establishing human habitation there.