I think it's A. Hope this helps!
World War I, the Wright Brothers, the Russian Revolution, just to name a few events.
The progressive era of the 1900s impacts our lives to this day because it is perhaps the 'roots' of modern America, from motorcycles to the first flight.
Harappan Societies reached their heights around 2100 B.C.E, due to their advanced masonry and weaponry skills. Plus, they were good at trading resources with Mesopotamia. However little information is known of these societies because of the lack of their remnaents and almost no written records written by any of their people