The correct option for maintaining biodiversity in a managed ecosystem is B. Habitat restoration. Detailed Explanation Why Habitat Restoration is Correct:

1. Definition of Habitat Restoration: Habitat restoration involves the process of returning a degraded or destroyed ecosystem to a stable, healthy state. This can include replanting native vegetation, removing invasive species, and rehabilitating soil and water quality.
2. Biodiversity Benefits: Restoring habitats directly increases biodiversity by providing the necessary conditions for various species to thrive. Healthy ecosystems support a wide range of plants, animals, and microorganisms, which contribute to ecological balance and resilience.
3. Ecosystem Services: Restored habitats can enhance ecosystem services such as pollination, water purification, and carbon sequestration. These services are vital for human well-being and environmental health.
4. Long-term Sustainability: Habitat restoration promotes long-term sustainability by creating environments where species can adapt and evolve. This is crucial in the face of climate change and other anthropogenic pressures.
5. Community Involvement: Restoration projects often involve local communities, fostering a sense of stewardship and awareness about the importance of biodiversity.

Why the Other Options are Incorrect: A. Monoculture Farming: - Definition: Monoculture farming is the agricultural practice of growing a single crop species over a wide area for many consecutive years. - Impact on Biodiversity: This practice significantly reduces biodiversity as it eliminates various plant species and the animals that depend on them. It can lead to soil degradation, increased vulnerability to pests, and a loss of genetic diversity, making ecosystems less resilient. C. Overgrazing by Livestock: - Definition: Overgrazing occurs when livestock graze on vegetation beyond its ability to recover. - Impact on Biodiversity: This practice can lead to soil erosion, desertification, and the loss of native plant species. It disrupts the balance of the ecosystem, leading to a decline in species that rely on healthy vegetation for habitat and food. D. Urban Development: - Definition: Urban development refers to the expansion of cities and towns, often involving the conversion of natural landscapes into built environments. - Impact on Biodiversity: Urban development typically leads to habitat destruction, fragmentation, and pollution, which severely threaten local wildlife and plant species. It often results in a significant loss of biodiversity as natural habitats are replaced with impervious surfaces. Summary of Key Points

• Habitat restoration is the most effective practice for maintaining biodiversity as it actively works to improve and rehabilitate ecosystems.
• Monoculture farming, overgrazing, and urban development all negatively impact biodiversity by degrading habitats and reducing species variety.
• Restored habitats support a wider range of species and enhance ecosystem services, contributing to ecological health and resilience.
• Engaging local communities in restoration efforts fosters awareness and stewardship of biodiversity.

By focusing on habitat restoration, we can create sustainable ecosystems that support diverse life forms and maintain ecological balance.