[单选题]
If a wave from one slit )/ k 3mhx yug,sqtf1coevw**2of a Young's double slit:gzpcji:ovo-ve,z /.y nu8, m experiment arrives at a point on the screen one-half wavelength behind the wave from the other slit, which is observed at that,vy:j o8zecunm pi, vg /:.-oz point?
A. bright fringe
B. dark fringe
C. gray fringe
D. multi-colored fringe