Question

Which of the following was a cause of war between the Greek and the Persian empires in the fifth century BCE? A. The Persian Empire was attempting to conquer Egypt. B. All Greeks were attempting to declare independence from Persia. C. The Greeks were attempting to conquer Babylon. D. The Persian Empire was punishing the Greeks for their support of a Greek uprising in Persian territory. 
Please help I tried to research it but its all confusing

Answer 1

I think it might be D. Although I am not a genius there were a few Greek uprisings and the Persians had one simple rule that you had to follow, don't ever, EVER betray them.

Answer 2

The answer is D. The Persian Empire was punishing the Greeks for their support of a Greek uprising in Persian territory.