How many haploid nuclei are present in a mature pollen grain?

Identify A to D

A diagrammatic view of a typical anatropous ovule is given above. In which of the following alf five parts labelled as $\mathrm{A}, \mathrm{B}, \mathrm{C}, \mathrm{D}$ and $\mathrm{E}$ are correctly identified.

In the above figure the hydrophily is of

Identify structures $\mathrm{A}, \mathrm{B}, \mathrm{C}$ and phenomena $-{\mathrm{P}}_1,{\mathrm{P}}_2,{\mathrm{P}}_3$

The above diagram shows megasporogenesis and development of typical female gametophyte in angiosperms. In which of the following options all divisions $\left({\mathrm{D}}_1\text{ to }{\mathrm{D}}_5\right)$ and structure  S (S) are correctly identified