The correct answer is: c) The Neolithic Period.
The Neolithic Period is the last part of the Stone Age, when humans began to farm and live in settled communities. This period began around 10,000 years ago and lasted until the Bronze Age, which began around 3,300 years ago.
There is evidence of human presence in Sikkim dating back to the Neolithic Period. In 2003, archaeologists discovered a stone tool workshop in the state. The tools found at the workshop date back to around 7,000 years ago. This suggests that humans were living in Sikkim and using stone tools during the Neolithic Period.
The other options are incorrect because they do not correspond to the time period when humans first arrived in Sikkim. The Paleolithic Period (Lower, Middle, Upper) lasted from around 2.5 million years ago to around 10,000 years ago. The Mesolithic Period lasted from around 10,000 years ago to around 8,000 years ago. The Bronze Age lasted from around 3,300 years ago to around 1,200 years ago.
In conclusion, the correct answer to the question “Evidence suggests human presence in Sikkim dates back to:” is c) The Neolithic Period.