How can it be determined that the juvenile phase has ended in plants?

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$:
Assertion $A$: $A$ flower is defined as a modified shoot wherein the shoot apical meristem changes to a floral meristem.
Reason $R$: The internode of the shoot gets condensed to produce different floral appendages laterally at successive nodes instead of leaves.
In the light of the above statements,choose the correct answer from the options given below:

In angiosperms,the sporophylls are organised into:

Give differences: Accessory whorls and Essential whorls.

The term Anthesis is used for

Draw a labelled diagram of a typical flower.