One of the primary consequences of the railroad in the United States was the creation of a system by which goods could easily be moved east to west, opening new sections up that were previously only accessible by horse or on foot.
The colonists were unhappy with the way things were going. Each new tax was more of a burden than before and they eventually god fed up with it, which resulted with the Boston Tea Party, and the rest is history.
Let's look at all the options:
A. one of two types—social or working.
-there also also other kinds, for example family relations!
B. usually simple and easy to understand.
-this is not true. If it was true, there wouldn't be any inter-personal conflicts!
C. not influenced by people's ideas and attitudes.
-they are very influenced by people ideas! in fact, the opposite is true!
D. something that must be maintained to stay healthy and strong
-this is the correct answer! if the relations are not maintained, they will fade .
