Traditional practices like free-range grazing are still prevalent in:

The correct answer is: a) Hill districts of Manipur.

Free-range grazing is the practice of allowing livestock to graze freely on open rangeland. This practice is still prevalent in the hill districts of Manipur, where there is a large amount of open rangeland. The practice is beneficial to the environment, as it helps to control the growth of vegetation and prevent soil erosion. It is also beneficial to the livestock, as it allows them to graze on a variety of plants and grasses, which provides them with a balanced diet.

The other options are incorrect because:

• b) Imphal Valley is a densely populated area, and there is very little open rangeland.
• c) Coastal areas are often used for agriculture or other human activities, and there is little open rangeland available for grazing.
• d) Industrial zones are often located in urban areas, and there is no open rangeland available for grazing.