Which is the tallest tree?

The spur of $Pinus\ occelsa$ is

The diploxylic condition in $Cycas$ occurs in:

Plants in which seeds are produced on megasporophylls and are not enclosed by fruits are included in which group?

In which of the following aspects do $Gymnosperms$ differ from $Angiosperms$?

$A$: Microspores and megaspores are produced in the same lax in gymnosperms.
$R$: Lax represents a compact strobilus which bears microsporophyll and megasporophyll.