Be completely honest makes the most sense so D.
It goes out the uterus in a period.
A, B AB and O, O being the most useful, because O blood can be given to everyone, but also the most selective, since they can only receive O blood
Over the next few days, the single cell divides into multiple cells. At the same time, the small cluster of dividing cells moves through the fallopian tube to the lining of the uterus. There it implants and starts to grow. For 8 weeks after implantation, it is called an embryo.
An experiment should have only one independent variable.
