Which element does not exist in elemental state in the earth's crust?

Out of given four elements C, S, Fe and $\mathrm{Au}$, the non-metals $\mathrm{C}$ and $\mathrm{S}$ exist in elemental form as allotropes. $\mathrm{Au}$ is a less active metal. It also exists in nature as elemental form, called nugget. Fe is an electropositive metal. So, it exists in earth's crust in combined state (compounds), e.g. $\mathrm{Fe}_2 \mathrm{O}_3, \mathrm{Fe}_3 \mathrm{O}_4, \mathrm{FeS}_2$ etc.