The female reproductive part of bryophytes is:

Which of the following statements is correct about Marchantia?
$I.$ Plant body is thallus-like and closely attached to the substrate.
$II.$ Sporophyte is differentiated into foot,seta,and capsule.
$III.$ Gemma cups are located on the thalli.

Identify the plants $A$ and $B$ in the figures given below.

$A$ : In mosses,the second stage of the gametophyte consists of upright,slender axes bearing spirally arranged leaves.
$R$ : This stage of the gametophyte consists of sex organs.

Which of the following is true about bryophytes?

The protonema stage develops from $........$,and the leafy stage develops from $........$.