Consider the following statements: 1.The Eastern Ghats and Western Ghats meet at the Nilgiri Hills. 2.The Thar Desert is the most densely populated desert in the world. 3.The Patkai or Purvanchal ranges are part of the Eastern Himalayas. 4.The Satpura range is formed by a series of scarped plateaus on the south, generally at an elevation varying between 300-400 m above the mean sea level Which of the statements above is/are correct?