Which of the Following Is Most Likely a Proper Application

Which of the following is most likely a proper application of a BFOQ?

A) transferring pregnant women out of a department that worked with chemicals known to be harmful to a fetus
B) not hiring women for the night shift because the factory is in a very dangerous part of town and the company parking lot requires a ½ mile walk to the site
C) requiring airline pilots to retire at 60 years old
D) requiring all airline employees to retire at 60 years old