According to Stephen Kay, how does tap water differ from bottled water is: B. The quality of tap drinking water is inconsistent among municipal markets.
A. The production of tap water is heavily monitored to ensure it is safe to drink. While Kay might acknowledge this, it doesn't highlight a specific difference between tap and bottled water.
C. Tap water is inarguably the cheapest and best choice for drinking water. This aligns more with the perspective of tap water advocates, not necessarily Kay's position as a representative of the bottled water industry.
D. Tap water provides everyone with convenient, high quality drinking water. This statement is too positive and doesn't address the potential inconsistency Kay might highlight.
Therefore, option B reflects the industry perspective by acknowledging a potential quality difference between tap water in different regions, potentially justifying bottled water as an alternative in some cases.