In tundra ecosystems, the active layer of the soil thaws to a depth of only 30 cm to 100 cm during the brief summer. Which statement correctly explains how this cold environment's soil and climatic conditions determine both the shallow, lateral root systems and the low-growing cushion morphology of plants like the Arctic poppy (Papaver radicatumPapaver\ radicatumPapaver radicatum)?
The impermeable permafrost beneath the active layer prevents deeper root penetration, restricting root growth to the thin thawed zone, while the low-lying cushion shape keeps the plant within the warmer boundary layer near the ground and reduces damage from freezing winds.
Frequent cryoturbation in the top 10 cm10\text{ cm}10 cm of the active layer requires deep taproots to anchor the plant, while the cushion structure prevents the plant from absorbing excessive ultraviolet radiation at high latitudes.
Anaerobic conditions in the permanently unfrozen talik layer force roots to grow horizontally along the surface, while the low-growing morphology ensures the plant remains completely submerged in meltwater during the winter freeze.
Rapid solifluction down gentle slopes of 5∘5^\circ5∘ to 10∘10^\circ10∘ requires wide root networks to prevent downslope displacement, while dwarf heights are selected to minimize transpiration during periods of high humidity and fog.
