The diagram illustrates an arrangement set up to show two-source interference with coherent light of a single wavelength $\lambda$. An interference pattern is seen on a screen $3.0\,\text{m}$ from slits X and Y, and the slit separation is $1.0\,\text{mm}$. The central bright fringe is located at Q, and P is the second bright fringe from the centre. What is the separation between Q and P?
- A$6.0 \times 10^{3}\,\lambda$
- B$3.0 \times 10^{3}\,\lambda$
- C$6.7 \times 10^{-4}\,\lambda$
- D$3.3 \times 10^{-4}\,\lambda$