Correct Answer: Both assertion and reason are true, and the reason is the correct explanation of the assertion.

Solution : The correct answer is (a) Both assertion and reason are true, and the reason is the correct explanation of the assertion.

Horticulture does contribute to environmental conservation, and the reason for this is that it involves the plantation of trees and ornamental plants, which helps in maintaining ecological balance.Horticulture encompasses the cultivation of a wide variety of plants, including trees, shrubs, flowers, and ornamental plants. These plants have several environmental benefits that contribute to conservation efforts.

Firstly, the plantation of trees in horticulture plays a crucial role in environmental conservation. Trees help in combating climate change by absorbing carbon dioxide from the atmosphere through photosynthesis and sequestering it in their biomass. They also release oxygen, improve air quality, and provide shade, reducing the need for energy-intensive cooling systems. Trees help in reducing soil erosion, conserving water, and providing habitats for various animal species. Additionally, trees contribute to biodiversity conservation by supporting a diverse range of organisms.

Moreover, horticulture practices often promote sustainable techniques such as organic farming, water conservation, and the use of eco-friendly pest control methods. These practices reduce the environmental impact of agriculture and contribute to conservation efforts.

In conclusion, the assertion that horticulture contributes to environmental conservation is true, and the reason that it involves the plantation of trees and ornamental plants, which helps in maintaining ecological balance, is the correct explanation for this assertion.