Which of the following formulae represents mica?

The common formula for the mica group of minerals is ${\mathrm{XY}}_2-3\mathrm{Z}4010{(\mathrm{OH},\mathrm{F})}_2,$ where $\mathrm{X}=\mathrm{K},\mathrm{Na},\mathrm{Ba},\mathrm{Ca},\mathrm{Cs},\left(\mathrm{H}3\mathrm{O}\right),\left(\mathrm{NH}4\right);$$\mathrm{Y}=\mathrm{Al}, \mathrm{Mg}, {\mathrm{Fe}}^{2+},\mathrm{Li} ,\mathrm{Cr} ,\mathrm{Mn} ,\mathrm{V}, \mathrm{Zn}; \mathrm{and} \mathrm{Z}=\mathrm{Si},\mathrm{Al},{\mathrm{Fe}}^{3+},\mathrm{Be} ,\mathrm{Ti}$. In nature, end-member compositions are uncommon.

Thus ${\mathrm{KAlSi}}_3{\mathrm{O}}_{11}{\left(\mathrm{OH}\right)}_2$ is the correct answer