This question has options. Select from options: Read this fact: "damming a river can cause a lake to form"

Now answer this question: "A beaver is building a home in a river, and that eventually blocks up the river, giving the beaver a nice home. A side effect of the beaver's new home is"

Possible answers:
(A). a pool;
(B). freshwater body;
(C). a mountain;
(D). an ocean;
(B).