Before the Agricultural Revolution, many people lived in rural areas because

    Before the Agricultural Revolution, many people lived in rural areas because they have to grow and harvest their own crops, since there was not yet a mass market from which to buy food.                                                                                                                                                

what are local authorities doing to fix the problem

explanation:

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.