After one month of pregnancy, the embryo's $…A….$ is formed. By the end of the $…..B…$ month of pregnancy, the foetus develops limbs and digits. By the end of $\ldots$… most of the major organ systems are formed for example, the limbs and external genital organs are well-developed. By the end of $…D….$ the body is covered with fine hair, eyelids separate, and eyelashes are formed. Here$ A$ and $D$ refers to

Foetus is nourished by

Assertion : During fertilization only head of spermatozoa enters egg.

Reason : If several spermatozoa hit the egg at same time, all can enter the egg.

Identify $X$ from figure :

Relaxin hormone is produced from