The correct answer to this one is actually E. The belief of the parents is that rigorous organization will increase their child's cognitive development. The author disputes this belief by saying that a child with structured playtime will not be creative and resourceful. The problem with this response is that the author assumes cognitive development and creativity/resourcefulness are the same thing, when that is not necessarily true. This flaw is best expressed by E.
B is incorrect, because the enjoyment of playtime is irrelevant to this argument. We are talking about the cognitive effects of playtime.