The correct option is D I, II and III
Dormancy, or lack of seed germination, results from endogenous control, which means the conditions within the seed control the germination of the seed.
Delayed germination allows time before a proper dispersal of the seeds so that the seeds don't germinate all at one place. Also, it protects the seedlings from any chance of bad environmental conditions that the seed may come across.
There are several mechanisms within the seed that induce dormancy in seeds. Sometimes, the seed coat is impermeable to water and oxygen. Since a seed needs water and oxygen for germination, an impermeable seed coat leads to dormancy. When a seed coat is too hard, the embryo can't germinate.