Which of the following is not a group of flowering plants (Angiosperms)?

Which groups depend on an external source of free water for fertilization?

Cycas and Adiantum resemble each other in having:

Flagellated cells are absent in .........

When the sperms of $Funaria$ and $Pteris$ are put together near the archegonia of $Pteris$,only the sperms of $Pteris$ readily enter the archegonia and reach the egg. The reason being that

In $Funaria$ and $Pteris$,both sperms are released near the archegonium of $Pteris$. Only $Pteris$ sperms enter the archegonium because: