Answer:
The Harappans depended on annual monsoon winds to bring rain from the Indian Ocean to Southeast Asia.
Explanation:
All other factors, except monsoon, given in the options are hazardous as they cause destruction to wealth and life. So, for sure, Harappans won't depend on annual factors like these which would harm them instead of benefitting.
Furthermore, The cycle of monsoons can be observed following a pattern, and people can be somewhat sure about when to expect Rains. But tornadoes, floods, and hurricanes don't follow any such pattern and, thus, might not add in annual factors.
