Correct Option: B. An embankment Detailed Explanation:

1. Understanding Floodable Plains:
2. A floodable plain, also known as a floodplain, is an area adjacent to a river that is prone to flooding. These plains are typically flat and low-lying, making them susceptible to overflow during periods of heavy rainfall or snowmelt.
3. Purpose of an Embankment:
4. An embankment is a raised structure, often made of earth or other materials, designed to prevent flooding. It acts as a barrier that holds back water, allowing roads and other infrastructure to be built safely above the flood level.
5. Why an Embankment is Suitable for the Oke-Hatis Road:
6. Given that the Oke-Hatis Road passes through a floodable plain, constructing an embankment is a practical solution. The embankment elevates the road above potential floodwaters, ensuring that it remains passable even during flood events. This is crucial for maintaining transportation routes and accessibility in areas prone to flooding.
7. Construction Considerations:
8. When building an embankment, engineers must consider factors such as soil stability, drainage, and the potential for erosion. Proper design and materials are essential to ensure the embankment can withstand the forces of water during flooding.

Why the Other Options are Incorrect:

• A. A flyover:
• A flyover is an elevated road that allows traffic to pass over intersections or other roads. While it can be used in flood-prone areas, it is typically more expensive and complex to construct than an embankment. Additionally, flyovers are not specifically designed to manage floodwaters in the same way an embankment does.
• C. An underground passage:
• An underground passage, such as a tunnel, would not be practical in a floodable plain. If flooding occurs, water could easily enter the passage, making it unsafe and unusable. Moreover, constructing underground passages in flood-prone areas requires extensive drainage systems to prevent flooding, which complicates the design and increases costs.
• D. A road cutting:
• A road cutting involves excavating a path through a landscape, which can lead to increased vulnerability to flooding. In a floodable plain, a road cutting could become submerged during floods, making it an unsuitable option for maintaining a reliable transportation route.

Summary of Key Points:

• An embankment is a raised structure that protects roads from flooding.
• It is specifically designed to keep infrastructure above flood levels, making it ideal for floodable plains.
• Other options like flyovers, underground passages, and road cuttings are less effective or practical in flood-prone areas.
• Proper engineering and design are crucial for the effectiveness of embankments in flood management.

This understanding of floodable plains and the role of embankments is essential for geography students, especially when considering infrastructure development in vulnerable areas.