A popular ecotourism destination within the Simlipal Biosphere Reserve is known for its waterfalls: *

Barehipani and Joranda
Khandadhar
Duduma
Devkund

The correct answer is: a) Barehipani and Joranda.

Barehipani and Joranda are two of the most popular waterfalls in the Simlipal Biosphere Reserve. Barehipani is the highest waterfall in Odisha, with a drop of 300 feet. Joranda is a smaller waterfall, but it is still very beautiful. Both waterfalls are located in the core area of the reserve, and they are accessible by foot or by jeep.

Khandadhar is another popular waterfall in the Simlipal Biosphere Reserve. It is located in the southern part of the reserve, and it is a much larger waterfall than Barehipani or Joranda. Khandadhar is a popular tourist destination, and it is accessible by road.

Duduma is a waterfall located in the northern part of the Simlipal Biosphere Reserve. It is a smaller waterfall than Khandadhar, but it is still very beautiful. Duduma is a popular destination for hikers and nature lovers.

Devkund is a waterfall located in the western part of the Simlipal Biosphere Reserve. It is a small waterfall, but it is a popular destination for pilgrims. Devkund is believed to be a sacred place, and it is said that bathing in the waterfall can cure diseases.