$11.$ If the equilibrium constant $\backslash ($ K $\backslash )$ for a reaction is $5$ and the initial concentrations of reactants and products are both $1$ M$,$ the reaction quotient $\backslash ($ Q $\backslash )$ is $\_\_\_\_\_.$

$-$ a$)1$

$-$ b$)2$

$-$ c$)5$

$-$ d$)0\mathrm{.}5$