What is one problem the developing world faces? poverty falling birth rates aging workforce population decline

The correct answer is - poverty.

The developing world in general has a huge problem with poverty. Most of the developing world is in a very bad economic situation and is led by corrupt politicians, that contributes to the wealth and potential of the countries to be trapped by only few individuals, while the majority of the population is living in poverty, doesn't have access to basic things for life, the unemployment is huge, and the ones that work take just enough to be able to survive, and because of this there's huge amount of people that are trying to migrate to the more developed countries.

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: