Direct Observation of a Standing Wave Pattern Associated with Light

Direct observation of a standing wave pattern associated with light is difficult. The most relevant reason is that

A) the eye is insensitive to fluctuations in intensity that occur at those frequencies.
B) the eye cannot resolve a pattern with that spacing.
C) there is no convenient means of setting up the conditions for standing waves.
D) Hold it! In principle, light is not capable of producing standing waves.