Tanzanite is a gemstone used in jewellery. It is a hydrated calcium aluminium silicate mineral with chemical formula $\text{Ca}_2\text{Al}_x\text{Si}_y\text{O}_{12}(\text{OH})_6\cdot2\text{H}_2\text{O}$. The $M_r$ of tanzanite is $571.5$. Its percentage composition by mass is $14.04\%$ calcium, $14.17\%$ aluminium, $14.75\%$ silicon, $54.59\%$ oxygen and $2.45\%$ hydrogen. $(A_r$ values: H = $1.0$, O = $16.0$, Al = $27.0$, Si = $28.1$, Ca = $40.1)$ Determine the values of $x$ and $y$.
- A$x = 1,\ y = 1$
- B$x = 2,\ y = 3$
- C$x = 3,\ y = 3$
- D$x = 6,\ y = 1$