Answer:
When reading, you'll notice that the author primarily focuses on having the city change this, not the students or parents themselves. That rules out B and C. Furthermore, the author does not mention anything about the time the students get out, but rather, how dangerous the roads are. That rules out A.
I think the answer is D because of how much the author talks about the hazardous road conditions, so we can infer that the children are in danger when walking on Green Street.