A solution that has 0% salt isto a cell with 40% salt concentration

The solution is hypotonic

Explanation:

Molecules in a solution move from highly concentrated regions to regions of low concentration in an effort to reach a state of equilibrium- where the molecules are equally distributed. This always occurs with the molecules moving down the concentration gradient.

Solutions can be:

At 40% salt concentration, solution A is hypertonic while the less concentrated solution at 0% salt concentration is hypotonic.

it cools slower in the earth meaning the crystals have more time to form than lava on the surface