A Camera Lens Having a 50-Mm Focal Length Is Set $0.59 \mathrm {~mm}$

Multiple Choice

A camera lens having a 50-mm focal length is set to f/4.0. What is the minimum spacing of two objects located 12 m from the lens if the objects are just barely resolved in the image using light of
Wavelength 500 nm?

A) $0.59 \mathrm {~mm}$
B) $4.72 \mathrm {~mm}$
C) $0.024 \mathrm {~mm}$
D) $1.66 \mathrm {~mm}$
E) $4.9 \times 10 ^ { - 5 } \mathrm {~m}$