One potential limitation of the preferential looking technique is

One potential limitation of the preferential looking technique is
A.it cannot be used with grating stimuli
B.it cannot be used to test the acuity of infants younger than four months old
C.an infant may perceive a difference between two stimuli, but would look at each stimulus equally
D.all of these
Contrast senstivity functions are a plot of contrast sensitivity as a function of
A.spatial frequency
B.amplitude
C.pitch
D.wavelength