Give the name and atomic number of the inert gas atom in which the total number of d-electrons is equal to the difference between the numbers of total p and total s electrons.

Question

$\begin{array}{1 1}(a)\;Na ( atomic no.=23)\\(b)\;Kr ( atomic no.=36)\\(c)\;K ( atomic no.=26)\\(d)\;Ca ( atomic no.=40)\end{array}$