Final answer:
The angle between true north and the direction in which a compass needle points is known as the angle of declination. It is affected by the Earth's magnetic field and local variations, which cause the compass needle to align with Earth's magnetic poles. The correct option is b).
Step-by-step explanation:
The angle between true north and the direction in which a compass needle points is called the angle of declination. This angle varies depending on where you are on the Earth due to local variations in the Earth's magnetic field.
In contrast, magnetic inclination refers to the angle the compass needle makes with the horizontal plane, azimuth is a compass bearing measured in degrees clockwise from any direction, and elevation is the angle of an object above or below the horizontal plane.
Our compass needle example is directly related to Earth's magnetic field. The north pole of a compass needle is attracted to the Earth's north magnetic pole, which is located near the geographic North Pole.
Similarly, the south pole of the compass needle is attracted to the Earth's south magnetic pole, which is located near the geographic South Pole of Earth.
Furthermore, when discussing celestial coordinates like those for star positions, the term declination is also used but in a different context. Here, it refers to the angular distance north or south of the celestial equator. Option b) is the correct one.