What was a military effect of the fall of the Western Roman Empire?
O
The Huns united to take the city of Rome.
The Eastern Roman Empire became unstable and fell, too.
O The people reestablished the military and fought back.
The empire could not defend its borders against more invasions.

The empire could not defend its border against more invasions

Explanation:

The most straightforward theory for Western Rome's collapse pins the fall on a string of military losses sustained against outside forces. Rome had tangled with Germanic tribes for centuries, but by the 300s “barbarian” groups like the Goths had encroached beyond the Empire's borders. Invasions by Barbarian tribes.

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.

number 1 is a)