What is one of the author’s purposes in writing "The Thirsty Tree"? to show the futility of attempting to control the invasive salt cedar trees in the American Southwest

to show that the salt cedar tree is the most important of all trees now in the American Southwest landscape

to examine the history of environmental management in the American Southwest by focusing on the much-maligned salt cedar tree

to question the value of various interventions used to control the salt cedar tree in the American Southwest