Which orbitals are filled in given order in 6th period of periodic table?

According to $\mathrm{n}+1$ the rule, electrons will be filled in the following order of orbitals,

$5s\to 4d\to 5p$

In the sixth period (n=6) of the periodic table, 6s,4f, 6d, 6p orbitals are filled in the increasing order of the energy. A total of 16 orbitals are available, each of which contains a maximum of 2 electrons. Thus, a total of 32 electrons can be accommodated.

Hence, the option A is correct.