Answer:
A.
They have developed national pidgin languages.
Explanation:
The best example of how many pacific islands have adapted to a mix of different ethnic groups is that they have developed national pidgin languages.
This languages enable communication between this people of different ethnic groups.
A good example of this is the Melanesian Pidgin which is developed and spoken by Malaysians of different ethnic groups.
The correct answer is A. Reunifying several kingdoms
Explanation:
The Song Dynasty included around nineteen emperors who ruled China from the 10th century to the 13th century. This dynasty is recognized due to its multiple advancements in terms of government and culture. Indeed, during this dynasty, national paper money began to be used as part of the economy and a centralized government was established. This political change unified many kingdoms or territories in China as these were under the rule of the same emperor and share different elements including the use of the same currency.
British oppression of American colonies triggered political and civil unrest. Many protests were demonstrated which were vital events that led to American Revolution.
Explanation:
The British colonies in America suffered a shortage of money and lack of funds to trade their goods and British Crown had regulated the issue of paper money to American colonies through currency act which made colonies to bear huge price rise of commodities.
Sugar and stamp and tea act were implied on sugar, tea and other printed materials which oppressed the American colonies to bear heavy taxes. Quartering act forced the American colonies to provide food and shelter. Boston tea party act which forced the patriots to dump huge loads of tea leaves sacks into the sea.
The answer is Human
While the other options are always affecting the ecosystems, humans have a greater affect than all of the above