The electron configuration of Actinides are gives as

Question

$ (a)\;(4f)^{1-14}(5d)^{0-1} (6S)^2 \\(b)\;(4f)^{1-13}(5d)^{0-1}(7S)^2 \\ (c)\;(5f)^{1-14}(6d)^{0-1}(7s)^2 \\ (d)\;(5f)^{0-1}(6d)^{1-14}(7s)^2 $