A and B particles can only enter the collection chamber when they move linearly along O2 and O3 directions. V=EB can be obtained from qvB=qE, so the device can screen particles with specific speed. So, A is right and B is wrong.

C, d in electric field, according to kinetic energy theorem? QU= 12mv2, and v=2qUm, and v=EB, and 2qUm=EB. If the injected particles have the same charge and the mass m is certain, then the particles screened by this device must have the same mass. If the injected particles have the same mass, the particles screened by the device must have the same charge amount. So, C is right and D is wrong.

So choose AC.