The function of elaters is

In a moss capsule,the number of peristome whorls is:

In the given figure of $Sphagnum$,what do $A$ and $B$ represent?

Which of the following is not a part of the moss gametophyte?

$A$: $Riccia$ is a very simple and primitive bryophyte.
$R$: In $Riccia$,the zygote undergoes division to form an embryo after fertilization.

In mosses,the structure that produces gametes is formed by which of the following?