Many industrialized nations are trying to reduce atmospheric concentrations of carbon dioxide, a gas released by the burning of fossil fuels. One proposal is to replace conventional cement, which is made with calcium carbonate, by a new "eco-cement. " This new cement, made with magnesium carbonate, absorbs large amount of carbon dioxide when exposed to the atmosphere. Ttherefore, using eco-cement for new concrete building projects will significantly help reduce atmospheric concentrations of carbon dioxide. Which of the following, if true, most strengthens the argument?
A: Eco-cement is strengthened when absorbed carbon dioxide reacts with the cement.
B: The cost of magnesium carbonate, currently greater than the cost of calcium carbonate, probably will fall as more magnesium carbonate is used in cement manufacture.
C: The manufacture of eco-cement uses considerably less fossil fuel per unit of cement than the manufacture of conventional cement does.
D: Most building-industry groups are unaware of the development or vailability of eco-cement.
Choose A, B, C or D as your solution.
C