Final answer:
The Rayleigh criterion states that two images are just resolved when their diffraction patterns have the minimum angular separation such that one image's center overlays the other's first minimum.
Step-by-step explanation:
The statement that completes the resolution is: Two images are just resolved when the center of the diffraction pattern of one is directly over the central maximum of the diffraction pattern of the other. This is based on the Rayleigh criterion, which is a principle in physics that defines the minimum angular separation required to distinguish two close objects as separate. According to the Rayleigh criterion, two images are just resolvable when the center of the diffraction pattern of one is directly over the first minimum of the diffraction pattern of the other, meaning that their angular separation is adequate for them to be seen as two distinct objects.