What caused the final collapse of the western roman empire?

Invasions by Barbariam tribes. Rome had tangled with Germanic tribes for centuries, but by the 300s barbariam groups like the Goths had encroached beyond the Empires borders.

Hope this helps

seeing as no choices were provided, i'll do my best to answer it from knowledge.

job specialization promotes work ethic to the person doing the job. he/she may be strong in the arms and able to lift things, specializing him/her in a job where you lift and carry.

it was douglas macarthur..