As illustrated, two copper wires are connected together and a current flows through them. Wire P has diameter $d$, whereas wire Q has diameter $2d$. What is the ratio $\frac{\text{average drift speed of the free electrons in wire P}}{\text{average drift speed of the free electrons in wire Q}}$ ?
- A$\frac{1}{4}$
- B$\frac{1}{2}$
- C$2$
- D$4$