I can't choose the set of 3 chemicals with each of which Si will react (out of 5 possible sets)
$\ce{Si}$ does in fact react with $\ce{HF}$ and $\ce{NaOH}$. The reactions would be:

$$\ce{Si + 4HF -&gt; SiF4 + 2H2}$$

$$\ce{Si + 4NaOH -&gt; Na4SiO4 + 2H2}$$

$$\ce{Si + 2MgO -&gt; SiO2 + 2Mg}$$

You can conclude these, since $\ce{SiO2}$ is quite stable, and also reacts with $\ce{HF}$ and $\ce{NaOH}$ (You may have heard that $\ce{HF}$ dissolves glass), so definitely $\ce{Si}$ will react way better than $\ce{SiO2}$.