Legume seeds exhibit dormancy because of

Which of the following is not a man-made method to overcome seed dormancy?
$(I)$ Seed coat broken by using knives,sandpapers,etc.
$(II)$ Passage of seed through the digestive tract of animals.
$(III)$ Effect of inhibitory substances can be removed by subjecting the seeds to chilling conditions.
$(IV)$ By application of certain chemicals like gibberellic acid and nitrates.

In some plants,seed germination can be induced by mechanically breaking the hard seed coat. This phenomenon is known as:

Treatment of seed at low temperature under moist conditions to break its dormancy is called

Seed dormancy is caused by the presence of . . . . . . .

Choose the correct statement regarding seed dormancy.