Which pair of coordinates describes the position of a star's altitude?

The correct choice for describing a star's altitude is specifically tied to the terms used in coordinate systems that indicate the position of objects in the sky. Altitude refers to the angle of the star above the observer's local horizon, measured in degrees.

In astronomy, the term "altitude" is often paired with "azimuth," which describes the direction along the horizon that one should look to find the star. Azimuth is measured from the North point on the horizon, moving clockwise around to 360 degrees. Therefore, altitude and azimuth together give a complete description of a star’s position in the sky, making this choice accurate.

The other choices involve different coordinate systems not specifically representing altitude. Latitude and longitude are used to specify locations on the Earth’s surface. Right ascension and declination represent celestial coordinates that are analogous to latitude and longitude but are used for locating stars in the celestial sphere instead. Thus, they do not directly convey the altitude in the context of local observation.