Which of the Following Individuals Is Likely to Have a Longer-Than-Usual

Which of the following individuals is likely to have a longer-than-usual circadian rhythm?

A) Lisa, who has to get up every morning at 6:30 a.m., just before sunrise, to teach classes that begin at 8:00 a.m.
B) Dan, who has worked on a submarine far below the surface of the water for the last 3 months.
C) Jennifer, who works a usual 9 to 5 shift most days but is occasionally asked to work an overnight shift.
D) Ira, who spends most of his days working inside the "Bird House" at his city's local zoo.