An interference fringe pattern is formed with a red laser, a double slit and a screen. The screen is located $3.5\,\text{m}$ away from the double slit. The laser light has a wavelength of $640\,\text{nm}$. The fringe pattern is shown. What is the slit separation?
- A$1.2 \times 10^{-4}\,\text{m}$
- B$1.6 \times 10^{-4}\,\text{m}$
- C$3.1 \times 10^{-5}\,\text{m}$
- D$3.3 \times 10^{-9}\,\text{m}$