The correct answer is option 4: ecological balance. Keeping larger areas under forests is important for maintaining the balance and harmony in the environment. Forests play a vital role in sustaining biodiversity and providing habitats for various plant and animal species. They also contribute to the overall health of the ecosystem by regulating the climate, stabilizing soil, and conserving water resources. Forests act as carbon sinks, absorbing carbon dioxide from the atmosphere and helping to mitigate climate change. By maintaining larger areas under forests, we can ensure the preservation of these essential ecological functions. While options 1, 2, and 3 are all valid reasons for preserving forests, option 4 encompasses the overall importance of forests in maintaining the ecological balance.