Progesterone is secreted by ........

The first sign of a growing fetus can be noticed by:

Human placenta is derived from

The eutherian placenta is derived from,or in mammals,the placenta is formed by:

By which time of pregnancy are the limbs and digits developed in the fetus?

Major features of embryonic development at various months of pregnancy are given below. Choose the correct option for the correct sequential events.
$(i)$ The first movements of the foetus
$(II)$ The foetus develops limbs and digits
$(III)$ The embryo's heart is formed
$(IV)$ The body is covered with fine hairs