Question ID:PT65 S1 Q21 Passage:In several countries, to slow global warming, many farmers are planting trees on their land because of government incentives. These incentives arose from research indicating that vegetation absorbs carbon dioxide that might otherwise trap heat in the atmosphere. A recent study, however, indicates that trees absorb and store carbon dioxide less effectively than native grasses. Therefore, these incentives are helping to hasten global warming. Stem:The argument requires the assumption that Correct Answer Choice:DChoice A:trees not only absorb carbon dioxide but also emit it Choice B:most farmers do not plant any trees on their land unless there is an incentive to do so Choice C:land that has been deforested seldom later sustains native grasses Choice D:some of the trees planted in response to the incentives are planted where native grasses would otherwise be growing Choice E:few if any governments have been interested in promoting the growth of native grasses