[单选题]
A compound microscope is dew6s7gokf n5)wsigned to resolve objects rni9h8 hxv4* pwhich are 0.010 mm apart. If the focal length of the objective is 4.0 cm and the wavelength of light used is 550 nm, what is the diameter of the objective? 8nh*vx4pir9h
A. $0.27 \; mm$
B. $0.54 \; mm$
C. $2.7 \; mm$
D. $5.4 \; mm$
