Question

Read the passage given below and answer the question that follows. As used in the first paragraph, the word "stubborn" most nearly means — Passage: Long before engineers drew blueprints, nature was already prototyping. In the early 1990s the architect Mick Pearce faced a stubborn problem: how to keep a large office complex in Harare, Zimbabwe, cool without the punishing energy cost of conventional air conditioning. His teacher was an unlikely one — the termite. The mounds raised by Macrotermes termites hold an almost constant inner temperature while the world outside swings between scorching days and chilly nights. They manage it without machinery, through architecture alone: a maze of vents and tunnels that draws cool air up from underground chambers and lets warm air escape through a central chimney, the whole circulation driven by convection. Pearce and his engineers translated that logic into the Eastgate Centre. Its massive concrete frame soaks up heat by day and releases it after dark; fans pull cool night air through hollow floors while warm air rises and slips out through rooftop chimneys. The result startled even its builders: Eastgate consumes roughly a tenth of the energy of a comparable air-conditioned building, and its occupants, spared the dry recycled air of sealed offices, reported fewer respiratory complaints. Biomimicry — the discipline of borrowing design solutions from living systems — has since grown from curiosity into strategy. Yet its serious practitioners warn against a shallow reading of the idea. Copying the silhouette of a termite mound misses the point; grasping the principle, passive thermal regulation, is everything. Nature, they argue, is less a catalogue of shapes than a library of processes, refined over millions of years and free to any designer patient enough to study it.