The following graph of relative concentrations of the four hormones present in the blood plasma of a woman during her menstrual cycle. Identify the hormones $A, B, C$ and $D$

In man the foetal membrane which forms the intimate connection with the uterine tissue is

In embryonic stage RBC develops in

In some eggs, future organs can be demarcated even before cleavage begins. This type of development is called

The hormone that prepares and maintains the uterus during pregnancy is secreted by