Although `Cr^(3+)` and `Co^(2+)` ions have same number of unpaired electrons but the magnetic moment of `Cr^(3+)` is `3.87 B.M`. and that of `Co^(2+)` `4.87` B.M. because….
A. They have different no. of d electrons
B. They have same electronic but different orbital contribution
C. They have different electronic but same orbital contriguration
D. they are typical elements.