The magnetic nature of elements depends on the presence of unpaired electrons. Identify the configuration of the transition element, which shows the highest magnetic moment.

1.  3d7
2.  3d5
3.  3d8
4.  3d2

The greater the number of the unpaired electrons, the higher will be its value of the magnetic moment. Since 3d5 has 5 unpaired electrons hence the highest magnetic moment.
                               μ = 5(5+2)
   = 35
  = 5.95BM