In some pteridophytes, sporophylls form distinct compact structures called $A$ in $B$ and $C$. Here $A, B$, and $C$ refer to:

• A
  $A-sporocarp, B-Pogonatum, C-Selaginella$
• B
  $A-spikelet, B-Riccia, C-Marchantia$
• C
  $A-strobilus, B-Selaginella, C-Equisetum$
• D
  $A-spike, B-Fern, C-Salvinia$