The ovule of an angiosperm is technically known as:

Megasporangia arise from the ....

"Endostome and Exostome" are parts of the......

Select the correct option regarding megasporogenesis.

The ovule of angiosperms might be evolved from:

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: