Resolution defines the minimum separable distance in microscopy

Steps:

• Recall that microscope resolution measures the closest proximity of two points distinguishable as separate under optimal conditions.
• Evaluate choices against this: A describes image quality, not separation; B refers to field size; C matches the separation criterion; D confuses with detection limit.
• Confirm via Abbe's formula: resolution d = 0.61λ/NA, where λ is wavelength and NA is numerical aperture, directly tying to minimum distance.
• Select C as it precisely aligns with the optical definition.

Why C is correct:

• Resolution is the minimum distance between two objects that can be resolved as distinct, per Abbe's diffraction limit formula d = 0.61λ/NA.

Why the others are wrong:

• A: Describes image sharpness or contrast, not object separation.
• B: Refers to the field of view's span, unrelated to distinguishability.
• D: Indicates the smallest detectable single object, not the separation of two.

Final answer: C