Question

carbon dioxide emissions are known to have harmful environmental effects. because the cement industry is one of the biggest producers of carbon dioxide emissions, developing more sustainable processes for manufacturing cement is of major concern. researchers at columbia university have developed a method that uses seawater to make cement by converting magnesium ions, which are highly abundant in the oceans, into magnesium hydroxides that can then be turned into magnesium - based cement. according to the researchers, not only does the resulting cement not produce carbon dioxide, but it can actually improve the environment. which finding, if true, would most directly support the researchers claim? a the magnesium - based cement is more energy - intensive than is traditionally made cement. b cement is traditionally produced from carbon rather than magnesium. c the magnesium - based cement consumes carbon dioxide. d cement made from seawater is less costly to produce than is cement made from other methods.

Explanation:

The researchers claim that the new magnesium - based cement not only doesn't produce carbon dioxide but also improves the environment. If the cement consumes carbon dioxide, it directly supports the claim that it can have a positive environmental impact by reducing the amount of carbon dioxide in the atmosphere. Option A about energy - intensity is not relevant to environmental improvement in terms of carbon dioxide. Option B just states the traditional source of cement production and doesn't support the new cement's environmental benefits. Option D focuses on cost, not environmental improvement related to carbon dioxide.

Answer:

C. The magnesium - based cement consumes carbon dioxide.