Remark Good thing you tried to answer the question. At lease we know how to proceed.
A is wrong, because you can draw a conclusion.
B Remember that CD is constructed so that AB is cut in half. So the distance from CD to B is the same distance as CD to A. Choice B is true.
C is incorrect. CD can be extended to any length as long as CD goes through the point where the two arcs above and below AB meet are joined by C and D, then CD can be any length. In order words, CD can be any length.
The answer is 12 but the way you get it is you subtract 400 from 1000 which gives you 600 then you divide 600 by 50 to get 12. So it looks like this 1000-400= 600, 600/50=12. Hope this helps. :)
