The pair of reactions in a system with stoichiometric equations of Alongrightarrow$2$Bdots $(1)$ and Alongrightarrow C$...(2).50$mol of $A$ is fed to a batch reactor and the final product contains $5$mol of $A,80$mol of $B$ and $5$mol of $C.$ What is the percentage yietd of $B$ and fractional conversion of $A?$

$90\%$;$0\mathrm{.}8$

$80\%$;$0\mathrm{.}9$

$90\%$;$0\mathrm{.}9$

$80\%$;$0\mathrm{.}8$