The lack of a well-developed feudal system within Sikkim might be attributed to factors like:

The mountainous terrain
The relatively small population
The strong centralizing role of the Namgyal dynasty
All of the above

The correct answer is: d) All of the above

The mountainous terrain of Sikkim made it difficult for a feudal system to develop. The mountains made it difficult for people to travel and communicate, which made it difficult for a central government to control the population. The relatively small population of Sikkim also made it difficult to support a feudal system. A feudal system requires a large population of peasants to work the land and provide labor for the ruling class. Sikkim’s small population made it difficult to support a large ruling class.

The strong centralizing role of the Namgyal dynasty also contributed to the lack of a well-developed feudal system in Sikkim. The Namgyal dynasty was a powerful and centralized government that was able to control the population of Sikkim. This made it difficult for local lords to develop their own power bases and establish feudal systems.

In conclusion, the lack of a well-developed feudal system within Sikkim might be attributed to factors like the mountainous terrain, the relatively small population, and the strong centralizing role of the Namgyal dynasty.