Each of the following questions has a paragraph from which the last sentence has been deleted. From the given options, choose the one that completes the paragraph in the most appropriate way.
We can usefully think of theoretical models as maps, which help us navigate un familiar territory. The most accurate map that it is possible to construct would be of no practical use whatsoever, for it would be an exact replica, on exactly the same scale, of the place where we were. Good maps pull out the most important features and throw away a huge amount of much less valuable information. Of course, maps can be bad as well as good- witness the attempts by medieval Europe to produce a map of the world. In the same way, a bad theory, no matter how impressive itmay seem in principle, does little or nothing to help us understand a problem. ________
(1) But good theories, just like good maps, are invaluable, even if they are simplified.
(2) But good theories, just like good maps, will never represent unfamiliar concepts in detail.
(3) But good theories, just like good maps, need to balance detail and feasibility of representation.
(4) But good theories, just like good maps, are accurate only at a certain level ofabstraction.