Question

au stands for ______ and it is the distance between _____.

a astrology units; earth and the sun
b astrology units; earth and the nearest star
outside our solar system
c astronomical units; earth and the nearest star
outside our solar system
d astronomical units; earth and the sun

Explanation:

AU is the abbreviation for Astronomical Unit, which is defined as the average distance between Earth and the Sun. It is a standard unit in astronomy, not astrology (a pseudoscience). The nearest star outside our solar system is much farther away and not measured in AU.

Answer:

d. Astronomical units; Earth and the Sun