Dim Objects in the Dark Sometimes Disappear When You Look

Dim objects in the dark sometimes disappear when you look directly at them because_________________

A) the light from the dim objects falls on the blind spot
B) the light from the dim object is too weak to make it through the vitreous humor
C) the light from the dim object is scattered by the cornea
D) The light from the dim object is focused on cones in the fovea, which are less sensitive than rods