[单选题]
Light of wavelength 575 nm falls on a dou uph.zof0h 54tble-sl)xbepg+ 8e3n git and the third order bright fringe is see) ege x8+g3npbn at an angle of $6.5^{\circ}$. What is the separation between the double slits?
A. $5.0 \; mm$
B. $10 \; mm$
C. $15 \; mm$
D. $20 \; mm$
