The master plan for the new park calls for the planting of trees of any species native to this area, except for those native trees that grow to be very large, such as the cottonwood. The trees that the community group donated were purchased at Three Rivers Nursery, which sells mostly native trees and shrubs. Thus, the donated trees are probably consistent with the master plan. Which one of the following, if true, most strengthens the argument? ['Three Rivers Nursery sells cottonwood trees.', 'Three Rivers Nursery does not sell any tree species that grow to be very large.', 'Some tree species that grow to be very large are consistent with the master plan.', 'Tree species that are not native to this area and that are consistent with the master plan are rare and hard to find.']