Explanation:

Angstrom (Å), unit of length used chiefly in measuring wavelengths of light, equal to 10 -10 metre, or 0.1 nanometer. It is named for the 19th-century Swedish physicist Anders Jonas Ångström. Nautical Mile is a unit used in measuring distances at sea, equal to 1,852 metres (approximately 2,025 yards). Astronomical Unit (AU) is a unit of measurement equal to 149.6 million kilometres, the mean distance from the centre of the earth to the centre of the sun. Parsec is a unit of distance used in astronomy, equal to about 3.26 light years (3.086 × 1013 kilometres). One parsec corresponds to the distance at which the mean radius of the earth's orbit subtends an angle of one second of arc.