Physics: electricity

Please find the explanations as follows:

圖片參考：http://i117.photobucket.com/albums/o61/billy_hywung/April07/Electrostatics.jpg

So the answer is A.
(Note: Since in metallic structures, the atoms are closely packed that they are not free to move around, all charge flows are necessarily contributed by the movement of the "delocalized electrons" but not those "metallic ions". So if a metallic object is positively charged, the correct explanation should be "removal of electrons" and if it is negatively charged, the correct explanation should be "addition of electrons".)

answer is A
When the +ve rod is brought near X and X earthed, +ve charge is driven away and -ve charge remain on X, when +ve rod is removed, the -ve charge is even distributed among X and Y.