Why has the spread of the herbicide-resistant hydrilla through Florida’s waterways resulted in them no longer being navigable by most boats?

Hydrilla grows in dense underwater mats that can become tangled in boat propellers, preventing them from turning properly and propelling the boat. It does not cause drought, and the issue is not that sticky leaves hold boats in place. Therefore, the correct choice is “The weed clogs propellers that boats use for propulsion.”

AI-written and checked against the verified answer.