Why can grass plants be repeatedly mowed and still grow back?

Grass plants can be repeatedly mowed and still grow back because their growth region is subapical. This means that the primary area of growth in grass is found just above the soil surface, just below the leaf blades, and above the root system. When the grass is mowed, this subapical region remains intact, allowing the plant to continue its growth cycle.

The other options focus on different aspects of grass physiology. While deep roots can help in nutrient absorption and drought resistance, they do not directly relate to the capacity for regrowth after mowing. Broad leaves may assist in photosynthesis, but they do not influence the regrowth process following mowing. Nutrient storage in flowers is not pertinent for grasses, as they rely on the stored energy and nutrients primarily from roots and leaves for regrowth after cutting. Thus, the subapical growth region plays a crucial role in the grass's ability to recover and thrive even after frequent mowing.