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

The choices can be found elsewhere and as follows:

a.The 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

I think the correct answer is option A. The reason why waterways were no longer being navigable by most boats would be that the hydrilla has induced a drought that drained the waterways. Hope this helps.

Ithink it’s b but not 100% sure