[单选题]
If a wave from one slit of 4b:v txa+wb8 ia Young's doublege . ;8viwnmo:od5oi6 slit experiment arrives at a point on the screen one-half wavelength behvo di.i56w;o8 neo:gmind the wave from the other slit, which is observed at that point?
A. bright fringe
B. dark fringe
C. gray fringe
D. multi-colored fringe
