In which of these options do both constituents of the pair have the same magnetic moment?

Electronic configuration of ${\mathrm{Zn}}^{2+}=\left[\mathrm{Ar}\right]3{\mathrm{d}}^{10}$

${\mathrm{Cu}}^{+}=\left[\mathrm{Ar}\right]3{\mathrm{d}}^{10}$

${\mathrm{Zn}}^{2+}$and ${\mathrm{Cu}}^{+}$have a $3{\mathrm{d}}^{10}$ electrons in its 0 unpaired form. So, they both have the same magnetic properties. Electronic configuration of  ${\mathrm{Mn}}^{4+}=\left[\mathrm{Ar}\right]3{\mathrm{d}}^3$

${\mathrm{Co}}^{2+}=\left[\mathrm{Ar}\right]3{\mathrm{d}}^7$

${\mathrm{Mn}}^{4+}$has $3{\mathrm{d}}^3$ and ${\mathrm{Co}}^{2+}$has $3{\mathrm{d}}^7$.Three unpaired electrons are present in both electrical configurations. They therefore share the same magnetic property.
Both ions in the pair will have the same magnetic moment since they have the same number of unpaired electrons.