Consider the following grammar: What is $\text{FOLLOW}(Q)$?

To find $\text{FOLLOW}(Q)$, look at all production rules where $Q$ appears on the right-hand side:

1. In $P \to xQRS$, the symbol following $Q$ is $R$, so $\text{FOLLOW}(Q)$ includes $\text{FIRST}(RS)$.

2. Compute $\text{FIRST}(R)$:

   $$\text{FIRST}(R) = \{w, \varepsilon\}$$

3. Since $\varepsilon \in \text{FIRST}(R)$, we add $\text{FIRST}(S)$ to $\text{FOLLOW}(Q)$:

   $$\text{FIRST}(S) = \{y\}$$

4. Combining these gives:

   $$\text{FOLLOW}(Q) = (\text{FIRST}(R) \setminus \{\varepsilon\}) \cup \text{FIRST}(S) = \{w, y\}$$

Thus, $\text{FOLLOW}(Q) = \{w, y\}$, which corresponds to option (C).