Atomic number of Mn, Fe, Co and Ni are 25, 26 27 and 28 respectively.
Which of the following outer orbital octahedral complexes have same number of unpaired electrons?
[MnCl6]3–
Mn3+(3d4)
[CoF6]3–
Co3+ (3d6)
Both Co3+ and Mn3+ have the same number of unpaired electrons=4
Thus, Options A & C are the correct answers.