The correct answer is the Indus Valley civilization.
Aryan invasions, seasonal floods, earthquakes, rivers changing courses, and decline in trade, were all possible factors that led to the fall of the Indus Valley civilization.
The Indus Valley civilization was settled in a risky geographic area that was exposed to earthquakes, river floods, heavy rain, and the changing course of the Indus River. Some natural disasters destroyed their cities, impeding trade with other civilizations. Although Harappan cities were considered modern by the time, they probably succumbed to natural forces and invasions
The other options of the question were a) Mesopotamia, c) Mycenaean, and d) Egyptian.