An oak tree produces two kinds of leaves: large with shallow lobes and narrow with deep lobes. If this dimorphism is based solely on the ecological condition of amount of Sunlight exposure and no genetic difference exists between leaves that express either of the two forms, then a. the environment cannot affect the relative abundance of the two leaf forms. b. this must be a trait that expresses quantitative variation. c. natural selection cannot act on the trait of leaf morphology. d. natural selection cannot preferentially select one of the two leaf forms over the other. e. the large, shallow-lobed leaves must be adapted for Sunnier conditions.