Digital ACT Reading Practice Question #1693

As it is used in the passage, the word "perimeter" most nearly denotes a: Passage Excerpt (Literary Narrative): At fourteen thousand feet on the scree slopes of the Peruvian Andes, Clara paused to adjust to the thin, frigid air. Her leather field press was secured to her pack beside vials of ethanol and a scalpel. She was searching for a dwarf alpine cushion plant, Senecio microphyllus, reported only twice in nineteenth-century logs. In the valley below, colleagues collected in lush cloud forests where orchids rewarded an hour walk with dozens of specimens. But Clara was drawn to the perimeter of life—frost-raked rockfields where vegetation survived by reducing itself to tight, moss-like domes that trapped geothermal heat and resisted wind shear. When her boots revealed a carpet of golden star-shaped blossoms hugging the granite, Clara dropped to her knees. The harshness of the altitude made the survival of such fragile perfection seem miraculous.