The gestational age of the embryo is measured from when the sperm and egg unite.

a.
typically injected into the amniotic fluid
b.
typically injected into the mother's spine
c.
can be self-administered
d.
numbs the mother from the waist up

D.
numbs the mother from the waist up

Gestation is the process where the embryo or the fetus inside of a female is developing to become a fully developed infant. Hence, the period is called the gestation period and approximately is 9 months. 
Gestation can take place at numerous numbers which now is called multiple gestation. 

explanation:

two years ago, when picking flowers in the mountains back of yosemite valley, i found a book. it was blotted and storm-beaten; all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however; many of the inner pages were well preserved. and although all were more or less stained and torn, whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today; its granite pages have been torn and blurred by the same storms that wasted the castaway book.two years ago, when picking flowers in the mountains back of yosemite valley; i found a book. it was blotted and storm-beaten, all of its outer pages were mealy and crumbly. the paper seemed to dissolve like the snow beneath which it had been buried, however, many of the inner pages were well preserved. and although all were more or less stained and torn; whole chapters were easily readable. this is the condition of the great open book of yosemite glaciers today, its granite pages have been torn and blurred by the same storms that wasted the castaway book.

The answer is epidermis