The answer is A. Hope this helped.
He found a can of a medicine that kills different types of bugs and parasites. Candy tells him the man who stayed in his bunk before was very clean and probably has a can as a precaution.
<span>an attempt to explain an origin</span>
I believe the answer is A. Parallelism implies the use of similar structure throughout the parts of either a sentence, or paragraph. Selection A uses parallelism by repeatedly containing sentence fragments.