Which beaker contains ultrapure water based on conductivity meter readings?

Ultrapure water is characterized by extremely low conductivity levels because it contains very few ions or impurities. A conductivity meter measures the ability of water to conduct electrical current, which is directly related to the concentration of dissolved ions. The lower the conductivity reading, the purer the water.

If Beaker B has the lowest conductivity reading compared to the other beakers, it indicates that this beaker contains the fewest ions, and thus it is the most likely candidate for holding ultrapure water. The other beakers would show higher conductivity readings, suggesting that they have more dissolved substances, such as minerals or salts, which would make their water less pure.

So, the identification of Beaker B as containing ultrapure water hinges on its conductivity reading being significantly lower than those of the other options, which are indicative of higher levels of impurities.