Correct Option
The correct option is (a).
Explanation
A plateau is an elevated flat land, often described as a flat-topped tableland standing above the surrounding area. It is one of the major landforms on Earth, alongside mountains and plains.
Statement-wise Analysis
- Statement 1 is Correct: A plateau is characterized by a large, relatively flat surface on top. It may have one or more sides with steep slopes that clearly demarcate it from the surrounding lowland or plains.
- Statement 2 is Incorrect: The height of plateaus is not uniform globally. Their elevation varies significantly, ranging from a few hundred meters to several thousand meters. For instance, the Tibetan Plateau is the highest in the world, with an elevation of 4,000 to 6,000 meters above mean sea level, while other plateaus like the Chotanagpur Plateau are much lower.
- Statement 3 is Incorrect: The Deccan Plateau is one of the oldest landmasses in India and the world. It was formed due to the volcanic fissure eruptions (Deccan Traps) and the breaking and drifting of the Gondwana land. It is not a young formation; rather, the Himalayas are examples of young fold mountains.
Key Takeaway
Plateaus are "tablelands" with steep slopes and highly variable elevations. The Deccan Plateau is an ancient stable block composed of old crystalline, igneous, and metamorphic rocks, unlike young geological formations.