A. An ovum is fertilized by a sperm and then divide into two, each forming a separate embryo B. an ovum fertilized by two sperms and then divides into two, each forming an embryo C. two ova are fertilized at the same tine each forming an embryo D. two ova are fertilized by a single sperm each forming an embryo after fertilization E. one ovum first divides into two and each half is fertilized by a sperm before developing into an embryo