Which phrase characterizes the way both sides fought World War I? They sent large armies to occupy heavily fortified defensive positions. They relied on air and naval power to bomb coastal population centers. They used mechanized units to move rapidly from one battle to another. They attacked industrial regions to destroy the other side’s industry.
The best option from the list would be that both sides "attacked industrial regions to destroy the other side’s industry," since this was the first "total war" in which nothing was technically "off limits" for attack.