Final answer:
Rezwan used a fleet of boats to transport students through the rising waters to different schools
Step-by-step explanation:
The sentence that best explains how Rezwan used the rising waters to solve a problem is: He used a fleet of boats to transport students through the rising waters to different schools. This sentence describes how Rezwan utilized the rising waters as a means of transportation to ensure that students could still attend school despite the challenging circumstances. By using a fleet of boats, Rezwan found a practical solution to help students continue their education.