Answer:
What doesn't stick to the common principles of map hierarchy is the placement of legend.
Explanation:
A is not correct because the placement of the title is situated well and in the right position.
B is not correct because the inset is situated well, where it doesn't obstruct the view, but also gives a better view of this particular area.
C is not correct because the bibliographic information is lacking.
D is correct because the placement of the legend should not be in the central part of the map, it should be in a bottom corner, where it is not obstructing the view of the main object.