The Renaissance Practice Test

Leonardo’s enduring focus was on uncovering how things actually work. He explored how components move, interact, and function—whether in gears and pulleys, in structures, in the flow of water, or in the human body—driving a habit of careful observation and practical experimentation. That broad curiosity about mechanisms and processes is exactly what the statement conveys, making it the best fit.

While he did work on military engineering and pursued many other interests, those are specific applications rather than the overall drive to understand the functioning of systems. Poetry, music, banking, and commerce don’t capture that experimental, mechanism-centered mindset.