There were rows of Coconut trees on the bank of the river.

Coconut trees are the correct answer because they are commonly found growing near rivers and other bodies of water. They thrive in tropical climates and are often planted along riverbanks for various reasons. Let's take a closer look at why Coconut trees are the most suitable option for this scenario.

1. Characteristics of Coconut trees:
- Coconut trees are tall and slender with a straight trunk. They can grow up to 30 meters in height.
- These trees have long and feathery leaves that can reach lengths of 4-6 meters.
- The leaves of Coconut trees are arranged in a spiral pattern along the trunk, giving them a distinctive appearance.
- The trunk of a Coconut tree is smooth and grayish-brown in color.
- Coconuts, the fruit of these trees, grow in clusters and have a hard outer shell, a fibrous husk, and a tasty inner flesh.

2. Habitat and Distribution:
- Coconut trees are native to tropical regions and are commonly found in countries such as India, the Philippines, Indonesia, and Thailand.
- They require a warm climate with high humidity and plenty of rainfall.
- Coconut trees prefer sandy soil and need access to water, which is why they are often found near rivers, lakes, or coastlines.

3. Benefits of planting Coconut trees along riverbanks:
- Coconut trees help stabilize the soil and prevent erosion, which is especially important along riverbanks where the water flow can be strong.
- Their extensive root systems bind the soil together, reducing the risk of landslides or riverbank collapse.
- The tall and dense foliage of Coconut trees provides shade, reducing the temperature of the riverbank and making it a pleasant place to relax.
- The coconuts produced by these trees are a valuable resource. They can be used for food, oil extraction, as well as in various industries.

In conclusion, Coconut trees are the most suitable option for rows of trees on the bank of the river because of their physical characteristics, natural habitat, and the benefits they provide in terms of soil stabilization, shade, and the production of valuable coconuts.