Why is the year 1492 considered a turning point
in history?
(1) the spanish established an exchange
between europe and the americas.
(2) the ming dynasty launched expeditions to
the east coast of africa.
(3) muslim arab armies succeeded in conquering egypt and syria.
(4) the british established control over new
territories in india.

1492 Is considered a turning point in history because 1) The spanish established an exchange between Europe and the Americas.

Explanation:

First of all, all of the options are important but only number 1) is why 1492 is considered a turning point in history.

In the first place, The ming dynasty launched expeditions to Africa between 1400 and 1430.

In the second place, Even though the fact that Muslim Arab armies succeeded in conquering Egypt and Syria is an amazing event, it was not a world event. It was local.

In third place, The fact that the British armies took control over territories in India was not so relevant, they already had powerful control over there.

However, the fact that the Spanish managed to discover a way to take the wealth of America away makes 1492 a turning point in history. Because it was a new continent filled with wealth. But note here, it was never an exchange because the natives were robbed and massacred. The only thing they got from it, were crimes.

the fact that could also be added to column b is that during world war ii, specifically between the years 1941 and 1945, japan expanded its territory towards the indonesian territory in what was known later as part of the "pacific war". in that time, japan could conquer the philipines, singapore,   borneo, central java, malang, cebu, sumatra and various other islands of the area, therefore expanding its territory for a brief period of time.

basic principles: federalism, separation of powers, checks and balances, judicial review, representative democracy, limited government, rule of law, individual rights and responsibilities, consent of the governed, majority rule, popular sovereignty, equal protection.