Formulae — practice question

Aluminium undergoes reaction with fluorine. $x\text{Al}(s) + y\text{F}_2(g) \rightarrow z\text{AlF}_3(s)$ What values of $x$, $y$ and $z$ make the equation balanced?

• A$x=1, y=2, z=1$
• B$x=2, y=3, z=2$
• C$x=3, y=2, z=3$
• D$x=4, y=3, z=4$