What develops inside the nucellus?

Given below are two statements: One is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A):$ $A$ typical unfertilised,angiosperm embryo sac at maturity is $8$-nucleate and $7$-celled.
Reason $(R):$ The egg apparatus has $2$ polar nuclei.
In the light of the above statements,choose the correct answer from the options given below:

In an embryo sac of a typical angiosperm,there are:

Describe the pistil (gynoecium).

The number of nuclei migrating from each of the micropylar quartet and chalazal quartet to the centre of the normal embryo sac is

The tissue that attaches the ovule to the inner side of the ovary is called .......