Transfer of pollen grains from the anther to the stigma is called pollination. Once the pollen grains are deposited on the stigma, the vegetative cell gives rise to the pollen tube. The pollen tube then enters into the embryo sac. The generative cell divides and gives rise to the male gametes. These gametes travel through the pollen tube and enter into the embryo sac. So, the correct sequence is option (c).