Answer: Option A
Explanation: The problem of increasing natural disasters due to increased population is actually related to southern asian countries like India and china. However, the problem of eastern asia is global warming.
In simple words, global warming refers to melting of ice-bergs due to increase in temperature. This increase has resulted in climate change and instability. Some continues of eastern asia are facing droughts while then other are coping with frequent tsunamis.
Thus, from the above we can conclude that the correct option is A.