Question

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

Answer 1

The correct answer is a.The hydrilla has induced a drought that drained the waterways.

Since it couldn't be removed with herbicides, it did just what is described in both the question and the answer, and it made the waterways no longer navigable.

Answer 2

Answer:

The answer is: b.-The weed clogs the propellers that the boats use for propulsion.

Explanation:

The South Florida Water Administration District (SFWMD) and the Florida Fish and Wildlife Conservation Commission  (FWC) are determined to begin on March 2, 2010 the significant effort to control the growth of the hydrilla on 1,745 acres of Cypress Lake. The invasive plant can clog waterways, prevent navigation and affect wildlife.

The answer is: b.-The weed clogs the propellers that the boats use for propulsion.