The arrow on the map is pointing to this that chinese trade as far back as 2500 years ago.
a) the great wall
b) the grand canal
c) the yangtze river
d) the huang he river

This is the Grand Canal that served to bring water from the south to the north of China. It served agriculture, navigation and trade purposes. The Great Wall runs from east to west in northern China. And the yellow line does not correspond to the course of either the Yangtze or the Huang He rivers.

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.