All of the following stages must occur for a woman to get pregnant. however, after which stage can a woman be described as pregnant?

Pregnancy is declared from the appearance of beta HCG hormone in the woman's urine or blood. 
The hormone HCG (Gonadotropic Chorionic Hormone) is secreted by the placenta from the implantation of the embryo into the uterus. If there has been fertilization, the HCG rate exceeds 8 IU at implantation and then starts to double every other day.
So we can conclude that pregnancy is described at the stage of implantation.

This type of galaxy is an approximately ellipsoidal shape and a smooth, nearly featureless image. they are the largest single star systems, in the universe and are built by the collisions of many smaller galaxies.

The answer is c the potato slice shriveled because water moved out of the slice into the salt solution