The causes of this horrible disease (are / is) poor diet and lack of exercise. » “Of this horrible disease” is a prepositional phrase. Eliminate it and we are left with "The causes,” a plural noun. Now, would we say “The causes is” or “The causes are?”

no its not a run on sentence however i think you meant wet suits not sours also a run on sentence would be like surfers surf all winter long in southern california by using wet sours to keep them warm and the live their all year long  

the answer is a.

explanation:

the clause "looking toward the south" modifies "a funnel cloud." it's not really the cloud that's "looking," but grammatically, that clause is modifying the cloud.

nhuijkn jkml; guhnjml

"the sandy walls seemed to collapse in on themselves"

and

"the bloodshot waters seemed to have no bottom"