What did people in both the north and the south have in common during the late 1800s people increased their use of both renewable and non-renewable natural resources.
a. people increased their use of both renewable and non-renewable natural resources
b. factories, railroads, and industry were more important to the economy than agriculture.
c. both groups of people understood that they needed to take care to protect natural resources.
d. people cut down forests for farming land, as it was the most important part of the economy

 People in both the North and the South  increased their use of both renewable and non-renewable natural resources during the late 1800s. Option A is correct.

From the late 1800's until today, fossil fuels, coal, petroleum, and natural natural gas have been the major sources of energy.

Renewable energy refers to the energy from sources that are naturally replenishing but flow-limited. They are virtually inexhaustible in duration but limited in the amount of energy that is available per unit of time.

nothing certain is known about what happened, but it seems that the country declined gradually, perhaps due to bad government, or, more likely, due to a series of bad harvests, which resulted in widespread and recurrent famine.

to act quickly in times of danger to the united states

because you have to act quickly if you want to live/survive.