The answer is D.
(Edited to combat confusion)
The term Boer<span> refers to white Afrikaans speaking farmers.
and the term </span> Afrikaner<span> refers, typically, to any white Afrikaans speaking person.</span>
Longitude is the angular distance of a place east or west of the Greenwich meridian, or west of the standard meridian of a celestial object, usually expressed in degrees and minutes.
The Polynesians developed the fine art of navigation by stars, inherited from the early arab navigators. Arabians used hand measures to measure the height of the star above the horizon to determine their latitude according to the angle determined.