ABCC$0.$ has an asset beta of $1\mathrm{.}05$ and a debt beta of $0\mathrm{.}8.$ Target debt$-$to$-$equity $($D$/$E$)$ ratio is $0\mathrm{.}6.$

With no taxes, what is the equity beta?

a$.1\mathrm{.}05$

b$.1\mathrm{.}20$

c$.0\mathrm{.}90$

d$.0\mathrm{.}65$