$A$: In $Funaria$,the sporophyte is parasitic on the gametophyte.
$R$: In $Funaria$,the main plant body is the gametophyte.

• A
  $A$ and $R$ are both true,and $R$ is the correct explanation of $A$.
• B
  $A$ and $R$ are both true,but $R$ is not the correct explanation of $A$.
• C
  $A$ is true and $R$ is false.
• D
  $A$ is false and $R$ is true.