Which of the Following Is True of the Number of Hours

Which of the following is true of the number of hours of daylight?

A) the number of hours of daylight includes the hours between dawn and twilight,not just the hours from sunrise to sunset.
B) the number of hours of daylight varies depending on the latitude of the observer.
C) the number of hours of daylight varies the most along the equator.
D) the number of hours of daylight varies the least at higher latitudes.
E) the number of hours of daylight is constant along the international date line.