An important wildlife sanctuary in Nagaland, known for its Mithun population, is:

Singphan Wildlife Sanctuary
Ntangki National Park
Puliebadze Wildlife Sanctuary
Rangapahar Wildlife Sanctuary

The correct answer is: b) Ntangki National Park.

Ntangki National Park is a national park in Nagaland, India. It is located in the Tuensang district, about 100 km from the state capital Kohima. The park was established in 1986 and covers an area of 1,400 sq km.

The park is home to a variety of wildlife, including tigers, leopards, elephants, deer, and birds. It is also home to a large population of Mithun, a type of wild cattle.

The park is a popular tourist destination and offers a variety of activities, including trekking, camping, and bird watching.

The other options are incorrect because:

  • Singphan Wildlife Sanctuary is a wildlife sanctuary in Nagaland, India. It is located in the Wokha district, about 150 km from the state capital Kohima. The sanctuary was established in 1989 and covers an area of 1,000 sq km. The sanctuary is home to a variety of wildlife, including tigers, leopards, elephants, deer, and birds.
  • Puliebadze Wildlife Sanctuary is a wildlife sanctuary in Nagaland, India. It is located in the Mokokchung district, about 200 km from the state capital Kohima. The sanctuary was established in 1989 and covers an area of 1,200 sq km. The sanctuary is home to a variety of wildlife, including tigers, leopards, elephants, deer, and birds.
  • Rangapahar Wildlife Sanctuary is a wildlife sanctuary in Nagaland, India. It is located in the Dimapur district, about 50 km from the state capital Kohima. The sanctuary was established in 1985 and covers an area of 600 sq km. The sanctuary is home to a variety of wildlife, including tigers, leopards, elephants, deer, and birds.