James Richards and Martyn Caldwell Conducted an Experiment to Test

Multiple Choice

James Richards and Martyn Caldwell conducted an experiment to test the hypothesis that hydraulic lift occurs in Artemisia tridentata,a species of sagebrush common in the western United States.Each plant in the experimental group was covered with an opaque plastic bag for more than two days to prevent photosynthesis and greatly reduce transpiration,and control plants were left uncovered.Fluctuations in soil water potential were measured,and other aspects of the experimental systems were observed.Which of the following observations from such an experiment provides the strongest support for the occurrence of hydraulic lift in A.tridentata?

A) finding,in the experimental plants,the water potential of upper roots to be greater than that of the leaves
B) finding,in the experimental plants,the water potential of the lower roots to be greater than that of the upper roots
C) finding,in the experimental plants,the water potential of the lower roots to be less than that of the upper roots
D) finding the shallow soil beneath the experimental plants to be drier than that beneath the control plants
E) finding the shallow soil beneath the experimental plants to be moister than that beneath the control plants