Which of the following has multiflagellate sperms?

Sporangia are associated with sporophylls. In $P$ plants,sporophylls are distinct,while in $Q$ plants,sporophylls form compact structures called strobili or cones.
$P \quad Q$

In aquatic ferns,the sporangia are found in a specialized structure called a sporocarp. This aquatic fern is .......

$Selaginella$ and $Salvinia$ are considered to represent a significant step towards seed habit because-

Which of the following is a heterosporous pteridophyte?

The rhizophore of $Selaginella$ is