Explanation: Bihar, located in the eastern part of India, has a rich biodiversity that includes a variety of plant species. The state's forests are home to numerous tree species, among which the Sal (Shorea robusta) and Teak (Tectona grandis) are particularly significant.
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 lacquer. The Sal tree also has medicinal properties and is an important source of food for wildlife, particularly the Indian elephant.
The Teak tree, another important species in Bihar, is a large deciduous tree that is highly valued for its durable and high-quality timber. Teak is used extensively in the construction of buildings, furniture, and boats. The tree is well-adapted to the climate of Bihar and is commonly found in the state's forests.
In contrast, the Oak tree (Quercus spp.) is not typically found in the natural forests of Bihar. Oak trees are generally associated with temperate regions and higher altitudes, which are not characteristic of Bihar's climate. The state's climate is predominantly tropical and subtropical, which is more suitable for the growth of Sal and Teak trees.
Therefore, the correct answer is (D) Only (A) & (B), as these trees are indeed grown in Bihar, while the Oak tree is not a native species to the region. Understanding the geographical distribution of plant species is crucial for comprehending the biodiversity and ecological characteristics of a region. This knowledge is particularly important for forestry, environmental conservation, and agricultural practices in Bihar.