Answer:
My answers is Mediterranean Sea.
Explanation:
If I need to choose only one answer it would be Mediterranean sea, as it was to the north to Egypt, which meant that it was impossible to attack Egypt from North without navy.
Red Sea can be also the correct answer as it protects Egypt from the east, although Sinai Peninsula connects Egypt with Asia.
Tigris and Euphrates are in Mesopotamia, not Egypt.
Nile is not correct as the river flows across Egypt and couldn't prevent invasion.
There are, moreover, two considerations particularly applicable to the federal system of America, which place that system in a very interesting point of view. First. In a single republic, all the power surrendered by the people is submitted to the administration of a single government;
I believe the correct answer is D, based on my general knowledge.
Hope I helped. ^ω^
Progressives lived in cities and believed that government could be tool for change they believed social problems were caused by industrialization and urbanization.
Answer:
I do not know this so sorry