Which was unknown in europe before european explorers visited the americas

onions

bananas

tobacco

sugar

Tobacco because it only grew in the Americas at the time

the answer wold be b) travel among nations should be regulated by an international organization

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.