Observe the following figures, and answer the following questions:
a. 
b. 
c. 
d. 
(i) Identify the stages (a) to (d) in figure during development of human baby.
a.
b.
c.
d.
(ii) Arrange the stages in correct sequence of development.
Answer variants:
Fusion of egg & sperm
Releasing of ovum from ovary
Implantation
A-B-D-C
Fertilisation
C-B-D-A
Zygote formation