In One Particular Case, the Limiting Angle of Resolution for an Eye

Multiple Choice

In one particular case, the limiting angle of resolution for an eye is $1.4 \times 10 ^ { - 4 } \mathrm { rad }$ . What is the minimum separation between two point sources of light that the eye can distinguish if they are at a distance of $40 \mathrm {~m}$ from the observer?

A) $2.8 \mathrm {~mm}$
B) $5.6 \mathrm {~mm}$
C) $8.4 \mathrm {~mm}$
D) $1.4 \mathrm {~mm}$
E) $4.7 \mathrm {~mm}$