A, ∫ This drawing can be overlapped with the original drawing after being rotated by180, ∴ This drawing is symmetrical about the central axis, so the option is correct;

B: This drawing can't overlap with the original drawing after being rotated by 180 ∴. This drawing is not centrosymmetric or axisymmetric, and the options are wrong.

C, this graph can overlap with the original graph after rotating180, and this graph is centrosymmetric, but not axisymmetric, so the option is wrong;

D: This graph can't overlap the original graph after rotating 180 ∴. This graph is not centrosymmetric, but axisymmetrical, so the option is wrong.

So choose: a.