Answer:
I would say that D, "One week later only one puppy remains, and the Coates family decides to keep him."
Explanation:
First, I would like to discuss the reason I would consider this sentences clear and concise.
We can see that is gives us a direct time, one week, instead of just "later."
We can see that it gives us an exact number of puppies left, one.
We can see that it gives us a gender, being male.
We can see that it gives us the actual name of the family, the Coates.
Now, lets talk about the falls of the other 3 senteces.
In A, it does not discuss how many puppies are being chased down.
In B, it does not discuss which neighbors bring leashes and does not establish what puppies needed to be controlled.
In C, it does not discuss what family will be watching the five puppies.
With the given information, I would choose D.
Hope this helps!