In flowering plants, gametes will grow into a new plant if the nuclei of the sperm and egg cells(male and female gametes) fuse. They will form an embryo plant. Another sperm nucleus and two polar cells will also join to form endosperm(food)for the embryo plant. Once this double fertilization occurs, a seed is formed and this can germinate into a new plant. A spore is a type of asexual reproductive cell which will be able to survive until conditions are favorable. Then, it will germinate into a prothallus, a plant that will give rise to male and female structures allowing the gametophyte stage to begin. Moss and ferns can reproduce with spores. Therefore, the correct answer is B.