The correct answer is Meghalaya.

• In India, tertiary coals occur in Assam, Arunachal Pradesh, Nagaland, and Meghalaya.
  • Tertiary coal is found in the rocks of the Oligocene period of the Tertiary Era.
  • Tertiary coal fields share only 1% of the coal production of India.
  • Tertiary coal is also known as 'brown coal'.
  • Tertiary coal contributes only about two per cent of the total coal production of the country. 
• Hence, option 2 is correct. 

• Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams.
  • Coal is the foremost power resources in India and is the most abundantly available fossil fuel.
  • India is highly dependent on coal for meeting its commercial energy requirements. 
  • Coal is found in a variety of forms depending on the degrees of compression and the depth and time of burial.
  • Types of Coal :
    •  Anthracite (more than 80% carbon content):
      •  In India, it is found only in Jammu and Kashmir.
    •  Bituminous (60 to 80 % Carbon Content):
      • It is the second-best quality of coal.
      • It is the most popular coal in commercial use.
    •  Peat (less than 40% carbon content)
    •  Lignite :
      •  It is low-grade brown coal, which is soft with high moisture content.
    • The principal lignite reserves are in Neyveli in Tamil Nadu and are used for the generation of electricity.
• The Damodar Valley Coalfield is the largest coalfield in India that extended to Jharkhand and West Bengal. 
• Jharia in Jharkhand is the largest coal mining field.