Which form of money has value only because the government says it does?

Currency.

In reality, governments' currency has no value or worth. The only reason they were useful is because they were backed by natural resources such as agricultural plants and gold, silver, etc.

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.