The correct answer is C. 14,000 years ago.
The last glacial period ended about 14,000 years ago. This was a time when the Earth’s climate was much colder than it is today, and large areas of the planet were covered in ice. The end of the last glacial period was a major turning point in Earth’s history, and it led to the development of modern human societies.
Option A is incorrect because 140 years ago is too recent. The last glacial period ended much earlier than that.
Option B is incorrect because 1,400 years ago is also too recent. The last glacial period ended much earlier than that.
Option D is incorrect because 140,000 years ago is too long ago. The last glacial period ended much more recently than that.