Why has the spread of the herbicide-resistant hydrilla through florida’s waterways resulted in them no longer being navigable by most boats? a. thy hydrilla has induced a drought that drained the waterways. b. the weed clogs propellers that boats use for propulsion. c. the sticky leaves of the weed hold boats in place. d. all of the above (not a nor d)

The correct option is B.
Herbicide resistant hydrilla which are found in the Florida water ways are resistant to herbicides, so there is no way of killing them or preventing their growth. This has made them to grow wild and untamed and they can be found everywhere in the length and breath of the water. When vessels are moving on the water, the weed typically disturb the vessels' propeller by clogging it and preventing it from moving the vessel forward. Because of this, many vessel owner usually avoid the water way.