Which of the following secretes the hormone relaxin during the later phase of pregnancy?

Which is the correct sequence in the development of man?

Human placenta is called haemochorial because . . . . . . .

Match the items $A, B, C, D$ of table $'A'$ with the items in table $'B'$. Then,the correct pairing sequence of $A, B, C, D$ will be:
Table $'A'$ | Table $'B'$
$A.$ Cleavage | $1.$ Formation of $3$ germ layers
$B.$ Gastrulation | $2.$ Formation of embryo spinal cord
$C.$ Neurulation | $3.$ Results in formation of skeleton and muscles from mesoderm
$D.$ Organogenesis | $4.$ Pattern depends on the amount and distribution of yolk

Choose the $CORRECT$ group of labelling.

Identify the stages $A$ and $B$; and what is the correct labelling of $C$ and $D$ in the process of human embryonic development?