Read the following context and answer the question.
Context: And by Sunday there were flooded streets ( including some major roads ) all over Chicago . Which , of course , entailed some necessary detours and basically insane traffic chaos in every direction . I went to see my parents on Sunday afternoon , and when I came back , nearly every street in my area was blocked off by the police . I almost drove back the 42 miles to my parents ' house to spend the night , since the possibility of finding a legal parking spot within walking distance of my building seemed like way too much to hope for .
Question: What may be the reason roads are closed because of flooding ?
Answer:


None of the above choices .