Digital SAT Reading and Writing Practice Question #572

Deep-sea hydrothermal vents emit superheated water rich in toxic minerals, creating environments where photosynthesis is impossible. Conventional marine biology holds that organisms here rely on chemosynthesis driven by sulfur compounds. However, marine geochemist Dr. Aris Thorne hypothesizes that a specific deep-sea bacterium, *Lithotrophicus profundus*, utilizes a radically different metabolic pathway. Thorne theorizes that *L. profundus* relies primarily on the oxidation of rare earth elements (REEs) rather than standard sulfur compounds to power its chemosynthesis. Furthermore, Thorne suggests that this specific metabolic preference makes the bacterium a 'lithoclast'—an organism that actively degrades the structural integrity of the rocky hydrothermal vent chimneys it inhabits as it extracts these embedded REEs. Which finding, if true, would most directly support Dr. Thorne's hypothesis?