Explanations:
Bihar, located in the eastern part of India, has a diverse range of flora, including several species of trees that are commercially and ecologically important. The forests of Bihar are known for their rich biodiversity, and among the trees that are commonly found are the Sal (Shorea robusta) and Teak (Tectona grandis).
The Sal tree is a deciduous hardwood tree that is native to the Indian subcontinent. It is widely distributed in the forests of Bihar and is known for its valuable timber, which is used in construction, furniture making, and for producing high-quality paper. The Sal tree is also important for its ecological role, as it provides habitat for various wildlife species and is a source of food for many animals.
Teak, another important tree species in Bihar, is a large deciduous tree that is native to tropical regions of Asia. It is highly valued for its durable and high-quality wood, which is resistant to rot and termites. Teak is extensively used in the construction of furniture, boats, and other wooden structures. The forests of Bihar have significant Teak plantations, which contribute to the state's timber industry.
In contrast, the Oak tree (Quercus spp.) is not commonly found in the forests of Bihar. Oak trees are typically associated with temperate regions and higher altitudes, which are not characteristic of Bihar's climate. The climate of Bihar is predominantly tropical, with hot summers and mild winters, making it unsuitable for the growth of Oak trees.
Therefore, the correct answer is that both Sal and Teak are grown in Bihar, making option D the correct choice. This question tests the knowledge of the geographical distribution of tree species and the specific climatic conditions that support their growth in the region.