In Pinus/gymnosperms, the haploid structure are (a) megaspore, endosperm and embryo (b) megaspore, pollen grain and endosperm (c) megaspore, integument and root (d) pollen grain, leaf and root.
Option B In Pinus/gymnosperms, endosperm is produced before fertilization and hence it is haploid. Megaspore and pollen grains are structures of male gametophytes and it is also haploid.
