The answer is D. All of the above, as different changes in the environment can lead to many different things.
There have been many government actions meant to help unify the nation, but the greatest was done when the Articles of Confederation were replaced by the Constitution, since this action put into place a much stronger-central government and "united" the states.
<span>With
the existence ever-evolving and incessant development of technology from the
past to the present century. People have been more digital and electronic, the “wireless
era”. Unlike the technology of the late 1800’s to early 1900’s it’s a tough and
took them a colossal step to actually use the existent device/s during this
age. With the turn of the 21st century, from trains, cars,
airplanes, to telephones, computers, and the most influential technology ever
developed yet is the turn of the internet which significantly boosted the urban
and cosmopolitan growth. How? In the sense of faster and wireless technology,
it promoted urban growth in many aspects –communication, locale and global
services, demands, industrialization, business and trade, and even people’s
lives through transportation, accessibility and ease of use. In the old days,
even letters and courier parcels takes days to be received, months and years to
travel and business was limited in the course of trade. It seemingly made all
the tedious processes of the early centuries to now at one touch to ripple at a
larger scale.</span>