What caused the fall of the Roman Empire?

a. defeat by Greece in the Pyrrhic War
b. lack of cultural cohesion
c. land region was too large to defend
d. peasant rebellion

I'd go with C, but there are different opinions. What does your text say?

In the linked webpages below, be sure to explore the external links and further references at the bottom of each page.
Fall of Rome - Why Did Rome Fall
Reasons for the Fall of Rome or the decline of the Roman Empire and reasons http://ancienthistory.about.com/cs/romefallarticles/a/fallofrome.htm

Decline of the Roman Empire - Wikipedia, the free encyclopedia
...the decay of trade and industry was not a cause of Rome's fall. There was a decline in agriculture and land was withdrawn from cultivation, in some cases ...
Overview - Highlights - Theories of a fall, decline ... - Historiography
http://en.wikipedia.org/wiki/Decline_of_the_Roman_Empire

CAUSES FOR THE FALL. OF THE ROMAN EMPIRE. A. By 476 AD Germanic invasions have. totally destroyed the old Roman Empire in the west. ...
(Broken Link Removed)

The fall of the Roman Empire is a complex event that resulted from a combination of various factors. It is important to note that it was a gradual decline rather than a sudden collapse. While there is no one single cause, some key factors that contributed to its fall include:

a. Defeat by Greece in the Pyrrhic War: This option is incorrect. The Pyrrhic War actually happened before the height of the Roman Empire and did not directly lead to its fall.

b. Lack of cultural cohesion: This option is partially correct. One of the reasons for the decline was the empire's struggle to maintain its cultural identity and unity. Over time, the Roman Empire became more diverse, with different cultures and traditions within its borders. This diversity created challenges in governance and maintaining a unified cultural identity.

c. Land region was too large to defend: This option is partially correct. The vast size of the Roman Empire made it difficult to defend its borders against external pressures. The empire stretched across three continents, leading to challenges in communication, military logistics, and defense against invading forces.

d. Peasant rebellion: This option is incorrect. While there were instances of internal unrest and peasant uprisings throughout Roman history, they were not the primary cause of the empire's fall.

Other factors that played significant roles in the fall of the Roman Empire include:

1. Economic Crisis: The empire faced financial strain due to constant military campaigns, increasing costs of maintaining a large bureaucracy, inflation, and the decline of trade routes. This led to economic instability and ultimately weakened the empire.

2. Barbarian Invasions: From the 3rd century onwards, the Roman Empire faced repeated invasions from Germanic tribes such as the Visigoths, Ostrogoths, Vandals, and others. These invasions put immense pressure on the Roman military and weakened the empire's ability to protect its borders.

3. Political Instability: The Roman Empire experienced frequent changes in leadership, including usurpations, civil wars, and a decline in effective governance. This political instability undermined stability and weakened the overall structure of the empire.

4. Rise of Christianity: The rise of Christianity had profound social and cultural impacts on the Roman Empire. It disrupted traditional religious beliefs and practices, challenged the authority of the emperor, and led to conflicts between pagans and Christians, contributing to divisions within the empire.

In conclusion, while no single factor can be solely blamed for the fall of the Roman Empire, the combination of economic, military, political, and social factors contributed to its gradual decline over several centuries.