Around the world, and beginning in the 1830s in the u. s., the growth of cities accelerated

a. as a result of a increase in the world's population.
b. during the industrial revolution.
c. during a major agricultural drought.
d. as more and more people learned to read and write.

B.during the Industrial Revolution.

Explanation:

During the industrial revolution there was a spectacular increase in population, mainly due to the fall in the death rate caused by the improvement of hygienic, sanitary and food conditions that was largely reflected in the reduction of infant mortality. In this period, the first vaccinations are born and the sewage and wastewater treatment systems are improved. A more abundant and regular diet, not subject to fluctuations in crops, lowered the incidence of epidemics and made possible the almost complete disappearance of catastrophic mortality, especially infant mortality.

During this period we also saw a large wave of people moving from the countryside to the cities, looking to improve their quality of life and better incomes.

the protestant reformation's started in 1517, disturbing the religious and political order in europe´s catholic countries. the outcome was the european wars of religion prosecuted in europe in the 16th, 17th and part of the 18th century. nonetheless, uprisings, territorial disputes, and great power conflicts were also causes of the wars.  

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation: