The term would be fracture.
One astronomical unit is equal to the distance from Earth to the Sun. The second option among all the options given in the question is the correct option. The distance as calculated in the year 2012 by the International Astronomical Union was equal to 149597870700 meters. Astronomers like to use this unit for measuring the distances between planets and other solar bodies.
Usually a hill or volcano I need the abcd things.
The correct answer is C: the Mackenzie River!