The correct answer is: A. midway between eye piece and objec-tive lens.
The cross hairs are placed midway between the eyepiece and the objective lens in order to provide a clear and accurate view of the target. If the cross hairs were placed closer to the eyepiece, they would be too large and would obscure the target. If they were placed closer to the objective lens, they would be too small and would be difficult to see. By placing them midway between the two, they are in the perfect position to provide a clear and accurate view of the target.
Option B is incorrect because the cross hairs would be too large and would obscure the target. Option C is incorrect because the cross hairs would be too small and would be difficult to see. Option D is incorrect because the cross hairs would not be in the perfect position to provide a clear and accurate view of the target.