What Was the Frost Line of the Solar System

What was the frost line of the solar system?

A) the distance from the Sun where temperatures were low enough for metals to condense,between the Sun and the present-day orbit of Mercury
B) the distance from the Sun where temperatures were low enough for rocks to condense,between the present-day orbits of Mercury and Venus
C) the distance from the Sun where temperatures were low enough for hydrogen compounds to condense into ices,between the present-day orbits of Mars and Jupiter
D) the distance from the Sun where temperatures were low enough for asteroids to form,between the present-day orbits of Venus and Earth
E) the distance from the Sun where temperatures were low enough for hydrogen and helium to condense,between the present-day orbits of Jupiter and Saturn