Movement between Bhabar and bugyal shows which depth of pastoral economy?

Correct answer: Use of different ecological zones in different seasons

The direct answer is D: movement between Bhabar and bugyal shows the use of different ecological zones in different seasons. Bhabar refers to the lower Himalayan foothill region, while bugyals are high-altitude grasslands. First, lower areas and high meadows do not have the same climate throughout the year. Second, snow and cold can make high pastures unavailable in winter, while warmer months open them for grazing. Third, herders moved between these zones so animals could obtain pasture at the right time. D is correct because it explains seasonal ecological adaptation. A is wrong because the system did not depend on one permanent place. B is wrong because these locations concern Himalayan land and pastures, not sea ports. C is wrong because the example is about grazing and seasonal movement, not mining or wage labour. Memory cue: different altitude, different season, different pasture.