Double Fertilization Reduces the Energetic Cost of Reproduction

Double fertilization reduces the energetic cost of reproduction.In gymnosperms,the female gametophyte stockpiles food for the embryo in advance of fertilization.The investment is wasted if no zygote ever forms.In contrast,double fertilization ensures that an angiosperm devotes energy to the zygote only if sperm fertilizes egg.What do the sperm fertilize in a double fertilization?

A) The egg
B) Two polar nuclei
C) The egg and two polar nuclei
D) The egg and zygote
E) The zygote