At which stage of embryonic development is cell differentiation observed?

The cavity formed during gastrulation is known as:

The gestation period of a rabbit is:

During embryogenesis,the zygote undergoes:

The allantois has the similar layers as present in the yolk sac. These are

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