Imagine two economists are debating whether 'AquaPura,' the sole bottler of water from a unique volcanic spring, is a monopoly. Economist A argues that AquaPura is a pure monopolist because it controls 100% of the market for 'AquaPura Volcanic Spring Water.' Economist B argues that AquaPura is not a monopolist because it only holds a 5% share of the broader 'bottled beverage' market. As a third economist, critically evaluate both arguments. Which argument provides a more realistic assessment of AquaPura's market power for regulatory purposes, and why? Justify your position by explaining the role of market definition in this analysis.