How many microspores are formed from a single microspore mother cell?

The saccus of $Pinus$ pollen is a modification of:

$A$: The generative cell comes to lie freely in the cytoplasm of the tube cell.
$R$: The cellulosic wall around the generative cell is dissolved.

The enzyme callase,which degrades the callose wall of the microspore tetrad to release four microspores,is provided by the:

In angiosperms, the male gametophyte is reduced to how many cells?

$A$: Each cell of the sporogenous tissue is capable of giving rise to a microspore tetrad.
$R$: The most abundant type of microspore tetrad is the product of simultaneous cytokinesis.