In Young's double-slit experiment, the slits are 2mm apart and are illuminated with a mixture of two wavelengths λ₀=750nm and λ=900nm. The minimum distance from the common central bright fringe on a screen 2m from the slits, where a bright fringe from one interference pattern coincides with a bright fringe from the other, is
A. 3 mm
B. 1.5 mm
C. 4.5 mm
D. 6 mm