The correct answer is 1 - iv, 2 - iii, 3 - ii, 4 - i.

• Nilgiri Hills are situated in Tamil Nadu.
  • Doddabetta is the highest peak of the Nilgiri hills.
  • Nilgiri hills are a part of the Western Ghats.
  • The hills are located at the tri-junction of the states Karnataka, Kerela, and Tamil Nadu.
  • These mountains are named after the Neelakurunji flowers (purplish-blue flowers) found in the Shola forests of Nilgiri hills.
  • Nilgiri Hills are known as the Blue Mountains.
• Satpura range comprises Satpura, Mahadeo hills, and Maikala hills.
  • Dhoopgarh is the highest peak of Mahadeo hills (Satpura ranges) located in Madhya Pradesh.
  • The Satpura range rises in eastern Gujarat running east through the border of Maharashtra and Madhya Pradesh and ends in Chhattisgarh.
• Mount Abu is the highest peak in the Aravalli Range of Rajasthan state in western India. 
  • It is located in the Sirohi district.
  • The highest peak on the mountain is Guru Shikhar, at 1722 meters above sea level.
  • It is referred to as ‘an oasis in the desert, as its heights are home to rivers, lakes, waterfalls and evergreen forests.
• Mt. Everest is the highest peak in the world with a height of 8840 meters above the mean sea level.
  • It is known as Sagarmatha in Nepal and Chomolungma in Tibet.
  • It is named after a Surveyor General of India George Everest.
  • The peak is located in the Mahalangur sub-range of the Himalayas.