The correct answer is: b) Hilly terrain.
Mizoram is a state in northeastern India. It is bordered by Assam to the north, Manipur to the east, Tripura to the south, and Bangladesh to the west. The state has a population of over 1.1 million people. The capital of Mizoram is Aizawl.
Mizoram is a hilly state with a rugged terrain. The state is home to the Mizo Hills, which are a part of the Eastern Himalayas. The highest peak in Mizoram is Mount Phawngpui, which is 2,157 meters (7,074 feet) tall.
The hilly terrain of Mizoram makes it difficult to build roads and railways. This is one of the reasons why the state lacks navigable waterways.
The other options are incorrect because:
- a) Extensive plains: Mizoram does not have extensive plains. The state is mostly hilly.
- c) Dense forests: Mizoram does have dense forests, but this is not the reason why the state lacks navigable waterways.
- d) Arid climate: Mizoram does not have an arid climate. The state has a humid subtropical climate.