Which of the following plants is susceptible to drawdown?

A waterlily is particularly susceptible to drawdown because it relies on a stable water level for its growth and development. When the water level decreases significantly, the plant may experience stress or mortality due to exposure of its root system and tubers to air. Waterlilies thrive in deeper, stable water environments, and a reduction in water levels can hinder their ability to photosynthesize effectively and can lead to desiccation.

Coontail, cattail, and sago pondweed have different adaptations that allow them to survive in various water level conditions. Coontail can tolerate some fluctuation in water levels; cattails are often found in wetlands that naturally experience drawdowns and can regenerate from established root systems; and sago pondweed is a submerged aquatic plant that can persist even when water levels fluctuate. Thus, the dependency of waterlilies on consistent water levels highlights their vulnerability to drawdown, making them the correct choice in this context.