Swollen petiole is present in:
Water hyacinth
Explanation of correct option:
1. Option C: Water hyacinth
Water hyacinth is a floating aquatic flowering plant that floats on the surface of the water. Petioles are spongy and form air-filled tissue.
Explanation for incorrect options:
2. Option A: Hydrilla
Hydrilla is an example of a submerged aquatic plant which have long, slender branching stems.
3. Option B: Vallisneria
Vallisneria is an example of a submerged aquatic plant that has ribbon-like leaves
4. Option D: Pine.
Pine is a tree that grows on the mountain it is a tall and straight tree with having cone-shaped appearance.
Final answer: Swollen petiole is present in Water hyacinth.