Doc is studying to be a police officer. In the middle of his written test, he is asked to write a short essay (800 words). He has to write about a danger that he sees that most police officers do not think about. Which of the following would make a good thesis for Doc's essay?
A.
Fences are used in neighborhoods all the time to separate yards, but we should use them to block off other things.
B.
Because many parks are near busy streets, there should be fences around the parks to protect the people in them.
C.
Many children play in parks, and the people who drive by parks often look away from the road to see happy children.
D.
In the United States, there are many different kinds of parks, from state and national parks to neighborhood parks.