It's not A because Lewis and Clark explored it.
I'm pretty sure the answer is D. from what I've researched the lands were really hard to farm on that the government had to pass a Homestead Act to get people to settle there.
There are only 4 reasons that the Indus River Valley may have ended but here they are.
<span>1.Aryans might have invaded </span>
<span>2.Drought </span>
<span>3.Indus River changed courses </span>
<span>4.Too much flooding and destroyed crops </span>
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<span>Well your wrong. How can there be a drought and excessive flooding? </span>
<span>The four reasons are: </span>
<span>1.) Aryan invasions </span>
<span>2.) Decreases in trade </span>
<span>3.) Recurring floods </span>
4.) Earthquakes and tectonic uplifts
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Actually, it is possible to have drought and flooding, just not at the same time, but that does not mean the first list is better.
<span>There is a link below to an article people can read to discover the latest official version of how the Harappan disappeared.</span>
