When an electron is added to elements of group $16$ and $17$ in $n = 2$ and $n = 3$ shells,which case experiences less electron-electron repulsion and why?

(B) The $n = 3$ shell experiences less electron-electron repulsion compared to the $n = 2$ shell.
This is because,in the $n = 3$ shell,the incoming electron occupies a larger volume of space,which reduces the effective electron-electron repulsion.