El Capitan Foods has a capital structure of $39\%$ debt and $61\%$ equity, its tax rate is $25\%,$ and its beta $($leveraged$)$ is $1\mathrm{.}55.$ Based on the Hamada equation, what would the firm's beta be if it used no debt, i$.$e$.,$ what is its unlevered beta, bu$?$ O a$.1\mathrm{.}34$ O b$.1\mathrm{.}20$ O c$.1\mathrm{.}05$ O d$.0\mathrm{.}95$ e$.0\mathrm{.}71$