Why do all copulations not lead to fertilisation and pregnancy? The root cause is

Following the diagram of an ovum surrounded by few sperms:

Which of the following option is correct for the labelled parts $\mathrm{A}, \mathrm{B}$ and $\mathrm{C}$ ?

Identify the stages $\mathrm{A}$ and $\mathrm{B}$ and select the correct labelling of $\mathrm{C}$ and $\mathrm{D}$.

Choose the correct option.