Assertion $(A) -$ In majority of angiosperms,there is monosporic type of embryo sac development.
Reason $(R) -$ The embryo sac develops from the single functional megaspore.

• A
  Both $(A)$ and $(R)$ are true and $(R)$ is the correct explanation of $(A)$.
• B
  Both $(A)$ and $(R)$ are true but $(R)$ is not the correct explanation of $(A)$.
• C
  $(A)$ is true but $(R)$ is false.
• D
  Both $(A)$ and $(R)$ are false.