The correct option is A √3 B.M., √0 B.M.
Electronic configuration of V = 1s22s22p63s23p64s23d3
Electronic configuration of V4+ = 1s22s22p63s23p63d1
So, number of unpaired electrons 'n' = 1
Magnetic moment = √n(n+2) B.M = √3 B.M.
Electronic configuration of Zn = 1s22s22p63s23p64s23d10
Electronic configuration for Zn2+ = 1s22s22p63s23p64s03d10
So. number of unpaired electrons 'n' = 0
Magnetic moment = √n(n+2) B.M = √0 B.M.