Question

nationalism was the result of modern industrial economy,justify this statement.

Answer 1

In short, nationalism is a fiction. There are no real, actual, natural nations - they're boundaries, ideologies and understandings that have come about through historical processes, just like every understanding of our societal relationships to others. I'm only American, for instance, because I reside inside of some borders that some white people made up way back when. The industrial revolution paved the way for nationalism because it gave humans access to unprecedented, massively powerful tools. A gallon of oil yields roughly 25,000 man-hours of human labor in terms of energy (discussion here), to give a sense of just how powerful these tools are.

Answer 2

Off course Nationalism (in Europe) was the result of modern industrial economy. The Industrial revolution had produced huge wealth and goods which need a large and unified market. This eventually led to the political integration of villages and regions in to a large state. This further created a group of skilled people trained in uniform school system and common communication. It lead to creation of a ‘national culture’ and  reinforced national boundaries. In this way, Modern industrial economy lead to the rise of nationalism.