Seed Dormancy

Abscisic acid, phenolic acid and para-ascorbic acid are inhibitors that govern seed dormancy. Gibberellic acid breaks seed dormancy – it activates the synthesis of $\alpha$-amylase, which breaks down stored starch into simple sugars. So gibberellic acid is not an inhibitory substance.

The seeds of many temperate plants, such as apple, peach and cherry, do not germinate until they have been exposed to a period of chilling.
Stratification is the treatment in which seeds are kept at a low temperature (about 0 to $10^\circ C$) under moist conditions for some weeks.
During this treatment the level of inhibitors such as abscisic acid falls and that of gibberellins rises, so dormancy is broken.
Scarification is the weakening or breaking of a hard seed coat by mechanical or chemical means.
Vernalisation is a low temperature treatment that promotes flowering, not the breaking of seed dormancy.
Chelation is the binding of metal ions by organic molecules.
So the treatment is called stratification.

Some seeds have hard, impermeable seed coats that do not allow water to enter, causing dormancy.
Scarification is the mechanical (rubbing, scratching) or chemical (acid treatment) breaking or weakening of the seed coat, which makes it permeable to water and gases.
Stratification is exposure of seeds to low temperature to break embryo dormancy, and vernalization is cold treatment to induce flowering.
So the seed coat becomes permeable to water by scarification.