Answer the following question given this paragraph: 

The placenta permits a long period of fetal growth in the uterus. As a result, the fetus can become large and mature before birth. This increases its chances of surviving.


Q: What allows for a large and mature fetus before birth,  resulting from a long period of fetal growth in the uterus?

 Choices:

- the vagina

- the cervix

- the ovaries

- the placenta

A:
the placenta
